Drop C isn't that low. It's higher than a low B.
I've been using it for years and have had everything from Eden XLTs to Schroeder to Berg to Mesa to Aguilar in that time frame. You don't need anything weird or crazy, from experience and not "guesses". A 410 may or may not give you more "low end", actual or perceived. It's going to give you more of a different character than anything and if you like the 12's, then stick with 'em. That's why I have two.
If you want a uniform rig, play each cab individually and see what you like best. Then sell the other, and buy another of the kind you kept. I'm usually not a fan of mixing drivers in a rig unless you're miking each one up for their different tonal properties.