Make sure the STI levers are 6703, not 6700. 6700 are double only, 6703 are either double or triple. Same for the derailleurs, triple derailleurs and yes 6603 front and rear are compatible with 6703 STI. AND yes that crank will work with the those components. I think the only issue may be that the 6603 front der, with a really deep inner cage, may hit the middle ring when the chain is on the large ring. You may need a 5603 FD who's crank is 50/39/30 also.