If you want TWO completely different sounding channels, the TNT is a great idea, I personally favor the tube channel myself, given its musicality and depth. The Cool channel is also a sick sounding preamp, but I tend to always reach for the TUBE channel on that box. The Cool channel has a lot of possibly to change the tone though. Overall the TNT has more gain than you'll ever need.
I think the TNT fits what your trying to achieve in having two different microphones for the same applications, it makes sense to me to be able to change the texture without adding any other processor into the chain. Just try the other channel if the tone doesn't cut it for the part.
Anyway, I think the TNT is a good choice, as well as the TRP [although its "straight wire with gain" and really has no character besides what your microphones offer which is a good thing but parred up against these others, its an entirely different animal] so perhaps its worth a shot to try a few things, as in this price range, there are a lot of microphone amps that shine with the microphones you own. I would strongly recommend that the NPNG 2NW is one of those amps. I think the 2NW [which is also upgradeable should you need MORE channels] would be the best option in my experience with these pairings, as it would make the MOST of what your microphones offer.