There's no such thing as a holland lop in the UK which may be why you're not having much luck, there are however lots of small lop breeds available for adoption -
http://www.rabbitrehome.org.uk/
This is a pro rescue forum and there are tens of thousands of rabbits looking for homes, the benefits of a rescue rabbit are that they usually come vet checked, neutered and vaccinated, so even though the adoption fee may look high it's actually really low compared to what you would be paying if you bought a cheap bun from a breeder and then had to get it neutered and vacced yourself
Neutering is essential if you want to keep rabbits together (they really should be kept in pairs), females especially have an enormous risk of uterine cancer if they haven't been neutered. It's also really important to get them vaccinated as there's a lot of myxomatosis and RHD going around at the moment, they previously only needed one vaccination (Nobivac myxo+RHD) but now they need Filavac RHD2 as well. Add up the neutering + 2 Vaccs and you're looking at at least £100 a rabbit. Also, as adorable as baby bunnies are, even the friendliest healthiest seeming babies can end up with health and behavioural problems whereas with an adult rabbit
If you do still decide to go with a breeder, I would advise you really look in to them. Do they have a facebook page or website with any reviews, and do people seem happy with the health of the rabbits they've bought and the way the breeder keeps their rabbits? Some breeders (eg. most BRC breeders that show their rabbits) will know the lineage of their rabbits really well so there's less of a chance you'll get a baby with some kind of genetic health problem. Other breeders (I call them back yard breeders) will just throw any two rabbits together without knowing their history. When you visit ask to look around where the rabbits are kept, if the parents don't seem fit and healthy, if any of the other rabbits look ill/sneezy, if they're offering you a rabbit under 8 weeks old, or if they're just generally not well kept then run a mile!
Also please give this guide a read, it's absolutely excellent, a must in my opinion for anyone considering rabbits
http://rabbitwelfare.co.uk/pdfs/RWAbrochuremaster.pdf