Hi Ali. I also live in the UK. I've just hatched a new leopard gecko that I'd like to place in a new home. She is a normal Leopard gecko but cute none the less and at the moment about 12 hours old.
(She should also be female.)
As for setting up a Viv and everything else I can give you all the info you need. For keeping a single Leo.
In England I've found it hard to find as many specialist stores as there seem to be in the US.
For a single leopard gecko you'll need....
-Viv. (As big as you can allow)
-UHT (Under Tank Heater) about 1/3rd the size of the viv.
-A light source normal light bulb works well.
-Hides (I use cork personally)
-Water dishes and Mealworm dish (if you want to use mealworms that is)
-Substrate. I personally use coral sand.
-Food Crickets/Mealworms/Hoppers
-Supplements for your Gecko. (Something with Calcium and other vitamins/minerals to coat your food items in.
Substrate many people don't like large grain sand or particle substrate due to worry about impactation. (Them swallowing it and becoming sick/dying) I personally in 8 or so years of knowing people who have kept Leopard geckos and snakes have yet to see this problem occur. I'm not saying it can't happen but I have not seen it.
I live in London and in a time if you want a Leopard gecko and have the correct setup I am more than happy to let you take this little lady from me for free.
My email address is leopardgecko@btinternet.com. If you have any questions feel free to email me.
Regards
Paul.