There are four main makers of titanium tubes which are columbus, dedacciai, reynolds and sandvik. They are all making nice quality of tubes, titanium can't be brazed but only tig welded. Titanium welds can crack with age. High end steels and especially new stainless steels are less prone to crack regarding welds or brazing because they have a higher resistance to fatigue.You need to have a certification in order to weld Titanium, and also have neutral gas chamber where it can be welded for avoiding contamination.