I have both combinations you ask about. With my 29 1/2" draw, I like each of them, but the A riser with the Dakota D limbs shoots better -- definitely smoother and maybe a little faster. The Mini-14 ILF riser with the C longbow limbs shoots just as well overall, if not better. I also recommend the foam/carbon limbs. They are expensive, but most people like them better in every respect, and they are fast too. There are some people who prefer the actionboo core Dakota limbs and some who prefer the Arapaho limbs. I don't and neither does Bob Morrison, but try all of them if you get the chance and see what you like best.
Allan