For hentai game - bassically all Illusion game (except the few VN like game they made), KISS (Custom maid serie), 3D custom girl (ie 3DCG - outdated graphically, but there tons and tons of mod by now) and it's failed sequel.
I think teatime game had some customization, but not that much (anyway they closed like half a dozen years ago sadly).
Fulltime (branch of Teatime I think) had some interesting stuff, but can't remember if there was some customization.
Miconisomi got some customization in its last games,but there just some specific h scene you use freely unlocked by story. You can swap from position to position without going back to some menu...
On western porn game, there some that offer that kind of freedom, but they got some bad review somehow, like 3D sex villa.
From memory, if you want good graphic quality, go for Illusion / Kiss work.
Tons of mod, it would be 3DCG.
Illusion's studio for their game allow to really make some customization. But it's hard work - you can create clothes ... but unless you know what to do, stick to mod...