hmm... with regards to the topic, well if you ask me, I'd go with 70-200 f4 IS, since you feel you're gonna sell your 70-200 2.8. i assume yours is of the non-IS variant.
among the 4 70-200s, most would agree that 70-200 f4 IS is the sharpest among the range.
as for whether f4 cuts it for indoor shoots, i'd say it probably would, if you're using the newer cameras with better high ISO performance. besides, comparing the 3 lenses TS has presented, the IS would probably help in many other situations besides indoor shoots.
if you've got a good range of primes, then get the 135F2 as another staple, as the sharpness for this prime is one of the best around. also fares very well in low light (pretty needless to say why). =D i personally would go (optimus) prime all the way if i had the deep pockets.