There are many milspec buffer tubes out there. I haven't tried Bravo Co's but it wouldn't surprise me if there tubes were great. My personal favorite is LMT but not too many vendors sell them separately. I usually use STAG which is made by CMT. Colt's buffer tubes are also made by CMT (4 position). They are much better than VLTOR from my personal experience as the threads tend to strip if you put too much torque on them.

Also, I have never had good luck using a strap wrench. I don't think you could get 40ft/lbs of torque on it.