As awesome as the one Super Record crank probably is, I'm pretty positive that two cranks that actually match is going to feel a lot better, even if they're cheap cranks as your saddle height is always going to be wrong for one of your legs with this setup.
Also, 177.5 is a stupid length unless you have really long legs or have a compelling reason to be using them. On the upstroke you're going to be raising your leg 15mm higher than you would with 170s and that personally sounds like a good way to get knee pains.