Right now I use SocalStreams.com , Holio's spring break, and a couple others inside dormangels.
I love SoCal's plugin. A lot of girls. Mostly pictures. Some good hardcore videos.
I don't like Holio's. Not updated enough. And my members don't really want to see the spring break stuff
I'm about to start up with
www.gotjizz.com - it's a really good price for quality of videos and girls.
For the amateur/college thing I have at dormangels - I think GotJizz will work really well.
I thought about amateurplugin - and have looked inside at their stuff. their prices are reasonable - but some of the girls are a bit older - they look 22-24+