I've just received a lovely tax rebate and want to spend £700 on starting in digital.

(could possibly push to £850 but would like to keep some back) I'm considering the new Canon 400 and would like to be able to get a good telephoto and macro lens. I've started doing some research and have lost my way in a world of teleconverters and ring flashes and have lost my confidence in knowing what I actually need!
The kind of images I'd like to take include -
macro - from very close up invert work to plants
tele - probably not birds, but most likely to use photographing mammals from distance i.e. deer from across a field, or full framed water vole from across a canal bank.
any ideas or advice most welcome.