Tavon, Quick, and Britt might have a chance at being nice depth receivers. Don't forget about Stedman Bailey too, he'll probably be getting some targets once he comes back. The problem in STL is we have so many potential targets that the players might have inconsistent stats each week. We don't have a set guy (not yet) that's always a #1 target, but once that person steps forward they might be valuable.
I wouldn't drop Austin cause he's more popular and wouldn't be as easy to grab later. Quick and Britt are pretty much invisible to the rest of the football world so you should be able to grab them any time.
Also, Cook could be a good depth TE if you need one.