[Hokum]

Hmm What would i get for £700-850.... hmmm that’s not actually very much...

I have no favouritism for any brand, I’ve used all the SLR's except Pentax. So you have a warranty I’d buy new, not used as when you begin your likely to get issues, and maybe want to return stuff.
As you starting out, your not looking to print bill boards so resolution isn’t that important. 6mp is enough to print A3 happily, and your unlikely to go bigger than that. You want a body with handles well, with rules out the 350D and 400D, for some of your work anti shake isn’t important so thats not a necessity. ISO performance maybe of use which leads me to one camera. The Nikon D50, its what i would buy if i was starting, its FAST!, it fits your hand well and it isn’t a slouch when it comes to ISO performance.
So thats £325 (remember you want good glass, thats the key)
Ok now we have a body lets look at lenses:
Macro? If it must be 1:1 then something like the sigma 105mm maybe of interest at £278.99 or for more flexibility the 1:2 the 28-105 D £249 which give you some zoom too. Cheaper macro would be 50mm sigma at £162.99
Telephoto? You seem to want about 400mm... thats an issue, the cheapest is about £430 on its own for the 135-400mm sigma (and i don’t rate it very highly)... So lets look at something else? The nikkor 300mm f4 is £865 so thats out, the sigma 100-300 is 749.99 which is too much. To put this into context... i just spent £2000 on a telephoto lens... So we are down to 300mm f5.6 lenses... which isn’t long enough for the vole, but ok for deer (with the sensor crop factor the FOV is of about 450mm) Sigma and Nikon offer lenses within £250 which cover this so that maybe of interest. But i’d make sure you get a Tpod too.

If your not wanting to GO SLR, i’d look at the Panasonic FZ-30 etc. Good range of zoom but poor ISO. But cheaper than most SLR lenses!