DO lenses ?

[Dallmeyer]

If needing 300 long, i would pass on a 200 of higher spec. It's a different tool from the one required.

if I remember right, you're looking at $1300-1400 for a 70-300 DO lens. If this is in your budget, then look into a 70-200 f/2.8L lens... or if you can afford a bit more, go with a 70-200 f/2.8L IS