As with everything in photography it depends on what the subject is, what the shooting situation is and what 'quality' you want the results to achieve,..ie what size reproduction, if any.
This shot is with an FD fit 100 to 300mm Tokina zoom from the late 60's used on a NEX 3 This lens has little monetary value and could be found in charity shops and similar but is capable of surprisingly high image quality with careful use and good technique. Manual focus is fast and efficient with long focal length objecives,...that's how we all managed before auto-focus! This shot was made quickly hand-held at the full 300mm but any suport of the lens will greatly increase image quality and this is vital if large reproduction in prints is envisaged. I have discovered that the NEX 3 itself is quite capable of excellent image quality at least up to 20x16 inch exhibition prints, but careful lens use/technique is vital.
I also have a Canon FD 70 to 210 f4 zoom from the mid 1980's which should be even better than the Tokina (although larger) Most if not all of the SLR makers made 70 to 200 size zooms and these can now be had on ebay for nominal sums,..all are capable of good results and might be a good place for you to start, all you need is the lens, and adaptor, plus some support aid such as bean bag/cusion/tripod etc.
NEX-3
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0mm
f/1.0
1/320s
ISO 800