High ride type Glock holsters...
If you want a good high ride type concealment rig for a Glock 20 10mm pistol, I'd look into the Safariland, Blade-tech, High Noon Holsters, Milt Sparks, Don Hume, Kramer, COM(Center of Mass), Galco, Alessi, Aker, or maybe Ted Blocker holsters.
Safariland's well made synthetic SFS belt rig may do well. Don Hume, Galco & Bianchi market good holsters too.
The popular Blackhawk CQC or maybe the SERPA polymer concealment rig may work with a big Glock 20 but these holsters are not "high ride" models.
Clyde F