RD and FD should be fine. I've done pairings that go the opposite direction. Ultegra 6700 derailleurs with RSX shifters and it worked perfectly. Not sure about the brakes, but I think it should be fine. If you can cross between brands, then that combo should work. Think about Tektro brakes. They work with any brand of levers.
Don't take my word for that last bit though!