I shop online at those store occasionally.
They do have nice look models, I particularly like Tyler Lough on International Jock but I don't think he's modeled any nude.
Justin Deeley formerly modeled for International Jock and he has done some nude, but I've never seen them around on the internet.
Renato Ferreira on Undergear is a more prominent Brazilian model, I don't think he's done full frontal nude, he has some nudes I believe, and there are of course underwear pictures where you can see VPL
Adam Ayash on Undergear apparently has a jerk off video on the internet, there's another thread about him on LSPG somewhere.
Will Grant on Undergear has some nice pics, but I don't think he has any full frontal nudes, not that there are any I can find on the internet.
Paul Marron is used a lot in Undergear, not sure of his nudes or if the exist.
Scott Herman has done some nice pics for Undergear and as far as I know he has no nudes, but lots of underwear and shirtless pics with VPL
James Guardino is also widely used on Undergear, can't find nudes for him, but possible?
Also I noticed Undergear used a former pornstar for one of their shoots, he has the two blue stars on his lower torso and the Cindy Crawford mole on his face...I don't know his name but I've seen him around.