As a newcomer in aircraft spotting I'll get soon a new dslr.
My choice is narrowed between D70/D70s/D50, final choice not yet done but as specifications are rather similar, the price may be the deciding factor.
About D50 is the 2,5 fps limit (vs 3 for D70(s)) a real drawback ?
About lenses, apart an all-round lens (probably 18-70 nikon or 18-200 sigma), I intend to buy a bigger lens for spotting.
But which one ?

Is 200mm enough or should I go for 300mm, given that with D70 the adjustment factor give 300 and 450 equivalent 35mm camera ?
Possible choice are :
Sigma 100-300 F4 (maybe my 1st choice)
Sigma 70-200 F2.8 (nice but is it enough ?)
Sigma 70-300 DG APO
Sigma 80-400 EX DG
Sigma 50-500
Nikon 80-200 2.8 (not VR)
Nikon 70-300 ED (already tested the non ED version, not really impressed)
I don't want to exceed 1000 €, so the superb nikon 70-200 vr is out of reach

I somebody could give me some feedback about these lenses, it'd be appreciated.
Thank in advance