Hunk Money - Nice all arounder here, loads of sites good tools and content to work with, choice of revshare or pps.
Bear Films - Good bear content which is usually tough one to find, these guys do it nicely.
Kinkydollars for your gay BDSM stuff (the boundgods site is awesome!)
Gunz Blazing - Some HOT videos available here plenty of different gay niches. Great quality
As for solo sites, im sure youve seen surfing around there arent so many especially not those kept up to date and worth it. Would be nice to see some twink ones starting up again but i guess the lads grow up and get bored aahhahahaa.
There are are a few sites with more mature solo guys you could try withmarcello.com is a popular one i can think of. He has been knocking around on the web for a long time i know he works hard to promote and update his sites. Butch Dixon is another.
I think
Intense Cash still run a few solo boy sites.
If i was you i'd forget the solo boy website stuff and perhaps sign up to someone with a ton of models and content like
curious cash work your way through those boys with a story about each etc..