For just normal street and track use, the regular ones are just fine. The BA or the Titan one is basically for dedicated track use, or as least I think so. Also, I'm not sure what Toyota was thinking with the BA ones, as you have to trim off the ends or else it'll break the speed sensors.
IMO, the stillens are the best bang for the buck - they are stiffer than stock, so the car will corner flatter; the rear is adjustable (although the one in the website pic does not show that) and yiu can shift the balence from understeering like a pig closer to neutral. They are also moderately priced, and the car ride does not suffer at all. A really good compromise for the guys who do most of their driving on the street, with a few DE events.
PS. Blaze is correct - the TRD and the stillen are the same. Get whichever you can get for less.