:wave: Oh dear poor you and poor bunnies, they don't sound very happy!
First things first I would suggest a trip to the vet - a bunny that screams is either absolutely terrified or in a great deal of pain, so it's best to eliminate a medical problem as a possibility first. Are they vaccinated? It might also be a good opportunity to get them checked over and given their vaccines
Also are they neutered? What gender are they? Sometimes hormones can make bunnies extremely territorial, resulting in biting and scratching especially when you put your hands in their territory e.g. to feed or clean them out, and getting them neutered will eliminate this hormonal territorial behavoiur. Sadly the number one reason for rabbits being handed into rescues is that the child got bored - usually because the pet does not want to be cuddled and is aggressive. Often the rescue finds that all it needs is for the rabbit to be neutered and many of these problems stop! Depending on the age and gender of your bunnies you may have to wait a little longer for this, and in the interim 'teenage tantrums' are pretty normal.
Assuming that the vet gives them a clean bill of health, it sounds at the moment as if you have two bunnies that are just terrified of people. Rabbits are prey animals so their instincts tell them that if they are being picked up, they are being carried off to be eaten (especially if they're being grabbed at because you know that they will bite you if you don't do it quickly). Most of us bunny owners will tell you that our bunnies don't really like being picked up - it's rabbit nature nothing specific to your two - and is in fact one of the reasons that rabbits don't make good pets for young children. Children want to pick up and cuddle their pets, and because of their prey instinces, rabbits in general are frightened by this. Even many people who say that their rabbits are good with their children do not realise that the rabbits are quiet and still because they are frightened, not because they are happy with the situation! Of course there will always be some that genuinely do not mind - but I have to say that this is the exception rather than the rule. If you do not succeed with getting to the stage where you can at least be comfortable with keeping these two (even if they are not the cuddly buns you wanted) I would honestly suggest not getting more, as you are sadly likely to end up with a similar situation, as rescues all over the country will tell you all too well.
I would suggest that you do not continue to pick them up and move them around, as this simply reinforces the behaviour and makes them even more afraid of you (biting and scratching in the way you have described, if not due to a medical condition or hormones, is often down to something called 'fear aggression'...in essence, they learn that by biting and scratching they can make you go away and leave them alone!
You need to get them to associate you with nice things. The easiest way to do this is to hand feed them. I have worked with rescues and fostered a number of seriously aggressive rabbits in the past and have had great success with some techniques...although I have to say the key is patience, it won't happen overnight, and maybe not even for a good few months. Some rabbits simply just don't like being handled, and it's far better to be able to provide them with a natural environment where they can just enjoy being bunnies and you and your son can enjoy watching them behave like bunnies. So I would suggest getting a run attached to the hutch if there isn't already, and giving them plenty of interesting things to do - they don't have to be expensive - several cardboard boxes arranged as hideouts, tubes etc are all great toys and stimulate the buns interest.
I would then get a book and sit in the run with them and completely ignore them. If you've had them a couple of months and they were initially babies, they are probably now getting to the age where they don't need unlimited food, so I would start restricting their dried food to a meal in the morning and evening (although always provide unlimited hay). Then when you sit in the run with them you can put some food on your lap and eventually curiosity will get the better of them and they will start coming over to investigate you. After some time they may start coming up and taking some food off you, and may eventually jump on your lap. The important thing is that it has to be on their terms - and if you move too quickly or try and move to the next stage too soon, you will end up making them scared again.
Also at food times I would put the food in your hand and place it at the edge of the hutch so they have to come towards you to get the food. If they would normally bite you when you do this, wear thick gardening gloves but it's important that you don't flinch your hand away - this will reinforce their behaviour and the sudden movement will also frighten them more. It may take a good few weeks before they are comfortable coming forwards and taking food from your hands. It's then a case of slowly putting your hand further inside the hutch with the food on it, then cupping your other hand over the top of the hand with food, so they get used to the sensation of being touched on their heads when they eat, and once they are used to this, you can start to stroke their heads.
Unfortunately there is no quick fix, it will take a long time, but they should come round in the end. If nothing else I would definitely suggest increasing their space and giving them a large attached run, as then they can enjoy being bunnies and you and your son can enjoy devising new toys and things to interest them, and then enjoy watching them investigate and play with the things you have made. Having it attached also means that they will get to be confident in their accommodation as it can unsettle them being moved around, and of course you won't need to pick them up to move them and they can be in the run while you clean them out. A friend of mine has a rescue where the buns have 30ft warrens to play in - yet far from causing these rabbits to be afraid of humans because they can avoid them, they actually all come running up to the gates to say 'hello'. Giving them plenty of space to fulfil their natural bunny instincts makes for happy confident bunnies
Good luck, please let us know how you get on.