Blade tech's are supposed to be quite decent. I have never used one myself however so I cannot comment from first hand experience. But they get good reviews from others that have used them. Pretty much as you said, a decent alternative to safariland.
As for making them yourself... You need a kydex press and mould, and a number of other misc. tools. Knyte Tactical, will actually be getting a kydex press and moulds soon for holsters, mag retention, knife sheaths, and other custom work...
Knifekits.com has the presses, foams, kydex sheets, and other tools, and you can find a lot of info on kydex forming if you, of course, google it.