On-line paintball stores, like all other e-commerce, is where the vast majority of the players buy equipment from. Below you'll find a number of links to sites that carry that new marker you just have to have, the replacement goggle lense so you can see and that self actuating/agitating/auto jam clearing hopper that you must have to top off your marker. If they make it, you can probably find it at one of these sites. If not, also check the manufacturer links page.
Action Village / Paintball Gear
Center Flag Paintball Products