Mcmaster is a bit too pricy for plain old fittings but if you're already ordering from them for some other reason, go for it.
Buyfittingsonline.com is by far the cheapest. I'd recommend 1/2" full couplings for the bulkhead and then you'd want to look at what thermometer and/or sight glasses you might want require. By far the most common thermometer thread is 1/2" but there are others out there. If you used my sight glass, right now it would be 1/4" thread.
I wouldn't JB weld. I'd use a weldless setup before I did that. If you have a propane torch you can thread a MAPP gas tank on and pick up a silver solder kit (not at lowes or depot). It's not hard to do but if it's your first time soldering anything, it might be a little intimidating.
Sightglass, Refractometer, Ball Valve, Weldless bulkhead, Thermometer, Decals, Stainless Steel Fittings, Compression Fittings, Camlock Quick Disconnects, Scale, RIMS tube, Plate Chiller, Chugger Pump, Super Clear Silicone Tubing, and more!New Stuff?