Sean i somewhat agree with Rooz.
i played around with the Tammy 70-200mm and the Sigma 70-200 HSM and the Tammy was pretty slow compared to the Sigma. pretty sure the Sony SSM will be much faster.
as for the body choice, i really can't comment since i'm not in your situation and not much of a sports fan. the a700 has awesome AF speeds so it has that going for it.
I agree, shooting challenging stuff is an exercise in frustration. Don did a lot to point this out to me early on. I was so stuck on capturing indoor candids that I missed a lot of great shots. Don't give up on the tough stuff, but it helps to get out and do something more fun once in a while. My trip to DC was a lot of fun, and really helped me get back into the swing of things.
Go shoot some trees or flowers or posed portraits or buildings. At 9am or at 6pm. Have fun with it. And the harsh piece of advice I can give you is to edit more. It is one of the hard truths of photography. I shoot less shots now, but try to focus on them more, and then I still only keep a very small number.
Catching up here guys, been out of town alot, and very busy with out internet access when away ARGHH!! anyway I value all the advice, And Rooz I like the way you think and speak your mind, thank you! Still frustrated, but going to try and have fun, Hope to take some long weekends late summer and into fall, and maybe try to turn them into 'field' schools for photography.