hello,
however I am not a professional in this subiect I can recomend behringer BCF2000 midi controller,
it has 8 motorised faders,
16 + 4 illuminated buttons freely assignable to all types of MIDI functions
and 4 virtual groups with 8 dual-mode encoders they can be pushed (for boolean function) or rotated and work same as faders.
For me it works fine and is quite cheap, with your budget you can buy 2-3 of them, or buy additional controler with different functions.
I paid about $100 for mine but the price is aroud $200 for new on eBay.
you can read about them here:
http://www.behringer.com/EN/Products/BCF2000.aspx
there is also different one:
http://www.behringer.com/EN/Products/BCR2000.aspx
Regards,
Jonek