Hello ncolwell,
I realize I am a bit late to the conversation but I also noticed you haven't posted a made decision yet either, plus this could be helpful to future readers. With so many great options in the glass/pyrex clearomizer world, it is really hard to go wrong with any choice when upgrading from plastic to glass.
Plastic should be avoided at all costs, especially things you touch or come into contact with. Plastic products release unhealthy chemicals into the blood stream including a chemical that is like the female sex hormone estrogen, even more so when the plastic starts breaking down. While I could write a whole college level essay on that subject, I will simply leave my comment at that for this post. With the final comment of, putting anything plastic to your lips is detrimental to your health, period.
Now as for a good choice for your husband's MVP 2, everything really comes down to personal preference, as with everything in the world of vaping, lol. The good news is that any tank on the market will be compatible with your husbands MVP 2. Tanks/clearomizers with replaceable coils these days are divided into two basic categories, single coil or dual coil. I have tried both but prefer the Kanger or Smok 1.8ohm single coils above anything else I have tried, they taste great and they are inexpensive when compared to a lot of other coils on the market. Since your whole setup seems to be made by Innokin, an obvious recommendation would be to try the Innokin iClear X.I Pyrex Glass Dual Coil Clearomizer, I personally haven't tried it because I think the price for the replacement coils is outrageous. On that note, I own and have tried over twenty various tanks, I have tried every single tank Kanger has, except for their plastic ones of course and I have to admit that I do really enjoy the Aerotank series, they are really great clearomizers. For portability, I would say go with the Aerotank Mini but keep in mind that all of the Aerotank's are dual coil. If your looking for a great single coil option, my two best recommendations are going to be either the Smok Aro II or the Anyvape Mini Davide. I own over thirty tanks and the one I use most often is the Smok Aro II, especially when I am out and about, surprisingly enough in it's favor, it is the absolute cheapest tank I own, lol go figure. It is a very simple two piece design much like your iClear 16 with one very important factor, it's not plastic, lol. Honestly I can't say enough positive things about the Smok Aro II, it has really blown me away and made me question the purchase of some of the $40+ tanks I own.
So my number one recommendation to you for you and your husband is the Smok Aro II for a single coil glass tank. I own five of them, lol!
SmokTech Pyrex Aro BCC Tank
Also, I personally haven't tried the Smoktech HBC, the reviews I read on it at Madvapes.com were mixed, half seem to love it while the other half seemed to complain about excessive leaking. For the price though, it certainly doesn't seem like a bad choice to at least give it a shot and see if it works for you. The large capacity certainly is appealing enough to give it a shot, lol. On a positive note, if you don't like the HBC, the coils you bought for it will also work in the Smok Aro II I recommended to you! =)