That link goes to a bunch of mods... Oh well...
I bought a tippmann awhile back and i have invested into some of these things:
Drop Foward: 32 degrees universal drop (i think is what its called)
Barrel: (because i am saving the awsome stock barrel for sale to the pros) I just sent in an order for a Lapco Big Shot 14 inch barrel, should do fine.
Hopper: (good investment) I am looking at all sorts of them right now, I have not come to a choice yet. Because there is a few of these out there to try, and i do not know hoppers to well. But they are better then my 5 dollar stock one that jams once in awhile.
But what MuddinPede_98C said in the order of upgrades i would say that is a good list in order.