I think Rival is the best for the money. Even though Apex is cheaper, there's a bit of extra weight for the money saved (I think).
If you can go for a mix of components.
Red shifters, Rival FD, Force RD, Red/DA cassette, KMC x-10 chain, Rival brakes (I usually recommend Planet X CNC brakes, they've got good reviews and are very light), and some stiff cranks (I've heard people complain about Force cranks not being stiff enough, but Ultegra being excellent).