Holster makers for a USP .45acp....
I'm sure you can find a decent rig for your .45acp pistol. USPs are not as common as the mid 1990s, but you can look around.
Depending on your budget, style of carry(open, field, concealed, etc) and choice(polymer, leather, nylon) I'd look here;
Safariland, Don Hume, Galco, Blade-tech, High Noon Holsters, Milt Sparks, Alessi, DeSantis, Kirkpatrick Leather, COM Holsters, Mernickle, Blackhawk.
I'd suggest a level II model for safety & retention.
If you buy a gun belt, get a lined format with a 1.5" or 1.75" width.
Some makers offer leathers like bull, horsehide or exotic too.
Every 2nd matters.