I would take A over B, though I'd be happy to get either.
A's stamina and durability are a huge selling point for me (he could pitch 7-8 innings a game in a 4-man rotation versus 6-7 innings in a 5-man rotation like B). B does have better control and splits which is impossible to deny, however A will still be comparable because his top pitch is a 97 which is a HUGE difference from B's ace pitch of 77. The higher GB and velocity make him a more versatile pitcher as well-- he'll strike out loads of guys, and when he doesn't, as long as you stock the middle of your infield with decent fielders this guy will be a Cy Young contender every year since he'll induce so many dribblers. B will still be a great pitcher, but his performance will suffer if he doesn't have a great defense behind him.
Again, it's a tough decision-- splits are more important than anything else in a pitcher's arsenal, making B possibly superior-- but I'd be happy to get either one. I'd probably just choose A. I'd be interested to see these guys' other ratings-- if one of them has really low makeup and patience, for example, I'd be inclined to choose the other. Either way you're looking at a very good pitcher.