I second the above. When I got my first pet that was really owned by me, back when I was 14 (gosh it seems a while ago lol) saving up the money and showing that I had done the research and was willing to pay myself, and do all of the work for the animal myself really helped me to convince my parents.
I was old enough to work and lucky enough to have family members I could work for, I used most of the money to save for my pet. If you are over 14 then perhaps look for a small weekend job or a paper round. Failing that you could offer to do things for family members (such as dog sitting, gardening, window cleaning etc) in return for a small charge. You would then be able to save the money up towards accommodation, adoption fees and insurance (although this may have to be take out in your parents names, with you giving them the money monthly) Also show your parents that you are concentrating on your education, and be as well behaved as possible.
Accommodation can be expensive, but you may be lucky enough to find a cheap shed, and you could pay towards the cost of fuel to have it delivered.
Maybe volunteer at a local rescue that re homes rabbits (this may depend on age, some ask children under a certain age - usually 14 or 16 to be accompanied by an adult when volunteering for safety reasons) That way you show that you are dedicated and that you fully understand how much hard work goes into keeping animals healthy and well cared for, with rabbits it is important that you are committed to looking after them for possibly ten years or even more as they do live that long.
The power point is a good idea, maybe include some information and quote it from well known welfare sites.
Most importantly do not bring it up around your parents to much if they do not agree yet. If they say no and give reasons just say ok, I understand your reasons and that .... such and such ..... You can then do some more research and save up more money and ask them again in the future..