Shure 55SH, zorg showed me a pic of one of the heads fitted with it, seems to work just fine!
If I decide to go that route, I may try to source the vintage 55S model as it has the hole drilled and threaded for the tubing already. I believe the 55SH model is a remake of the 55S anyway so the size should be the same. You can get them for around a $100 on eBay. Hopefully I can catch a deal somewhere on one.