Stat-wise, Escavalier is probably better, but it's only way of damaging steel types is Rock Smash, which is balls (A not very effective Megahorn actually does more than a super effective Rock Smash, if that says anything). Scizor gets Superpower, so he can dish out damage (sorta) against steels, though they're not that common in Black and White. Scizor also has a 90 Base Power (Factoring STAB) Priority in Bullet Punch, so it can pick of weakened pokemon or do enough to put it in KO range for the rest of your team. It's a matter of preference I guess. Escavalier hits harder and is a tiny bit bulkier, while Scizor has more utility.
Honestly, I don't think that basing Basculin around Double Edge is worth it considering the fact that Double-Edge is 120 Base and Waterfall is 80 Base + STAB (so the same, 120), and Water has around the same neutral coverage as normal type. I would say Adaptability is the way to go (provided you can find one), as Waterfall is now 160 Base Power (Adaptability changes the STAB modifier from 1.5x to 2x). Recoil doesn't really matter since Basculin's defenses are pretty terrible anyways, but I could see how Rock Head could be potentially useful.
Just my two cents.
And the Red 3DS looks awesome wtf.