Get on
@RogueGuy 's,
@Hookahhead_MD 's and
@GoodVibesBoro 's mailing lists and watch for glass DV stems and or try something like this:
Pure glass solution for your favorite 8mm tip solution. Works with Thermal Accumulator by PhattPiggie, Dynavap or Camouflet 8mm tips. Tapered glass mouthpiece serves as a 10mm male fitting. Includes: 1 pc of glass body1 pc of glass DNA Cooling piece1 pc of plastic clip 1 Carry Case Dynavap...
vgoodiez.com
Thicker nubbed glass stems are really nice for these. I have broken a thinner piece, so while a BB will work great it may be a little fragile in this context, ymmv.
EDIT: Hookahead already got you:
Handmade in the Mid-Atlantic United States! This 8mm adapter can be used to as a WPA for a Thermal Accumulator (pictured, but not included in sale, Dynavap tip and cap, Vaphit heater or other similar solution. 14mm Male to mate with your 14mm female waterpipe. Made by hand so please expect...
vgoodiez.com