Thanks a lot for the replies. Thankfully I seem to be relatively unharmed. I've managed to get a couple of pics which aren't very good but show that both stanchions are substantially bent. I can't really tell at this stage what further damage may have been caused (e.g. yokes, but these seem to be easily available on ebay for about £20-£30 for both the top and bottom ones, is it easy to check the frame?).
Looking at the photos of spare parts it seems that the actual stanchions on CBF600 (easier to find online than CBF500 ones) forks are identical but other parts of the forks are slightly different such as the bottom casings which have different part numbers compared to the 500. Are the stanchions all I really need (nothing internal should have been damaged? and assuming it wouldn't be worth it to try straightening these ones?) and my best course is getting hold of the stanchions as cheaply as possible and getting them simply swapped in to my fork legs, or am I better off holding on to find a pair of CBF500 forks?
Unfortunately I think I would have to pay someone to swap the stanchions in as according to the Haynes manual (which I downloaded immediately after purchasing bike, thanks husoi) 'rebuilding' the forks would have a 4/5 spanner difficulty rating meaning I'm not sure I have the confidence to attempt it myself and I'm dependant on the bike as my main mode of transport (am actually looking at buying another bike to use while I await this one getting fixed).
By the way husoi, "inexpensively" may be a better word than "cheaply", I want it fixed properly/well of course using quality used parts but don't want to spend more than necessary, I love it but can't get carried away, and I will be looking to upgrade/change at some stage.
Pics seem to be upside down. Sorry about that.