You must combine both studious and individual models! But first of all you need good traffic for your site because nobody will stay online on your site if they don't make money! If you don't have a lots of quality traffic then you must pay them at hour at least 1$/hour if they stay oline more then 20 hours at day (thats only an idea)! After your project will be ready I can tell you some forums where you can find models and studious, maybe you should also open a models refferal program!
Good luck
