Have a look at the used sections on these websites, all will give you 3-6 months warranty on used items, it will also give you some ideas as to price. On eBay I can recommend canon outlet (canon uk1) who do reconditions/return canon item with 1 year warranties and they usually have a large selection of SLR bodies.
http://stores.ebay.co.uk/Canon-Outlet
http://www.camtechuk.com/
https://secure.ffordes.com/index.htm
http://www.mpbphotographic.co.uk/
http://www.mifsuds.com/acatalog/ActChange.htm
http://www.parkcameras.com/
When it come down to what to choose, used or new, whether its Nikon or Canon, a 350D, 1D Mkii, D80 or D50 etc, it doesn't matter what body you buy (these tend to get replaced).
The lens is one of the important factors (%$*£ lens on front of camera, %$*£ images, but you don't have to spend stupid money to get a good lens).
Another important factor is really down to how you use it, a good technique and understanding of the camera + lens, its limitations and how to get the best out of it is more important than spending $$$$$.
If this is you first SLR a canon 350D or nikon D50 will get you started and won't break the bank balance, and they are very good camera's (forget about fps, spray and pray really only works on the professional ranges and you really don't want to get into this lazy habit, so a 350D would be fine).
As for a lens, (this is where the bigger chunk of $$$ unfortunately hits you) but a would seriously recommend something like the sigma 100-300mm f4 (£600-700), this is a great lens, very usuable zoom range, fast, sharp and will do most of the things you want. Also think about maybe a battery grip, which balances out the camera and lens. Hope this helps
Peter
