Just to clarify, what do you mean by, "in the $1000 range"? Of your entire list, only the 200mm f/2.8L II and the70-200mm f/4L (non-IS) fall under $1000. "Especially awesome" and "supertelephoto" and "$1000 dollar range" are mutually exclusive!


If by the $1K range you actually mean $1000-2000, I'd get one not on your list - the EF 100-400mm f/4.5-5.6L IS. It's versatile, has great IQ, and is the longest lens with IS that you'll find in that price range. That will have minimal functional overlap with any of the high-end primes (i.e., if you have the 300mm f/4L IS and the 300mm f/2.8 IS you're not going to carry both, but you might carry a fast prime and a slower zoom). The 100-400mm will also 'teach' you whether 300mm is adequate for your subjects, if 400mm is too short, etc.


If you actually mean $1K or less, get the 70-200mm f/4L (non-IS), but if you're set on primes, consider the 200mm f/2.8L II (I have one, it's quite nice!) and a 1.4x II teleconverter (the combo is a 280mm f/4 with very good IQ).