there are several options on the market from used to new, ranging from the 10rd SA17 spring feed to the Sport shot at 100rds,
the first question i would ask my self is, what size pods are you carrying to fill the hopper.
has several options for you
Empire/BT/what all other companies they -http://empirepaintball.com/
also has several to offer, from gravity feed to motorized.
Also, there are are a hole host of online dealers that can help you with either,
for example :
The final option would be buying used, and you can look here in the BST section and find just about any type of gear you would need.
Hope this helps, if you have anymore questions go a head and ask.