I do need a Machamp.. and this is what I have

Yup go for A, its a much more efficient option.

Yeah, that sounds right.

Besides, you may need the candy to evolve a second one in case the first Machamp gets garbage moves.

You're actually really well positioned compared to me.
I'm outside of heracross region, I've gotten one Machamp (100% iv's, 60 candy left - so I've gotten 185 candy, but most of it was from egg hatches; machop is really rare here) but it got DP/CC, so it's not very useful. And those are my only fighting mons other than garbage like primape and hitmons (and mine have crap movesets too). I've evolved 4 poliwrath since gen2 (I pineapp them, desperate for anything that can get that fighting advantage), no RS/DP, nothing with DP at all.

So you don't need a machamp particularly badly, you want one. I need a machamp (with usable moveset), very very badly.

That's too small of a difference in IVs to be worth the dust you'd have to spend (about 70k). Go for the high CP one, he'll turn into a Machamp with over 2300 which is very usable already.