May I throw a couple of suggestions your way Savo...
Depending on your budget - if you have £3,500 you can get a Canon 1d mark 2n and a Canon 100-400 IS Lens (I wouldnt consider anything under 300mm)
If you have under £600 you can get what I have - a 2nd hand Canon EOS 20D (with 18-55mmlens) and a Sigma 70-300mm
Beieve it or not there's not a
whole lot in between that I would consider.
Nikons would be a fair option also but I'm a Canon Man. Sigma lenses are the cheaper alternative to Nikon and Canon and can be bought for use with both.
As Ade says, get what you can afford BUT MAKE SURE you get a Digi SLR.
Below were both taken in Manual Focus as any lens and camera that's not a Pro spec just won't be up to auto-focus.
This was with the 70-300
This one with the 18-55
