DO NOT WASTE YOUR MONEY ON A FLATLINE BARREL!
Tippmann 98's are an excellent value and work quite reliably. A good friend of mine has been using his since it came out and it's still running well. They're easy to find parts and knowledgeable help on the field, which you will find is occasionally a lifesaver on game days. Get yourself a decent aftermarket barrel like a DYE, Armson, J&J, or CP, and a good Revolution hopper and you'll be set to go.
One thing to be certain of is DON'T WASTE YOUR MONEY ON A STUPID FLATLINE BARREL. Period. For your own sake don't do it. Yeah yeah they make the ball spin and fly far. But there are a few simple facts that are often overlooked (and lamented by those who bought them...if they don't acknoledge these faults they're just plain deluded, blind, or in severe denial):
1. The distance is not at all actually further than a decent aftermarket barrel of plain variety accomplishes.
2. The shots are themselves on the average not accurate at all.
3. The ball is decelerated significantly by the spinning, meaning that even if your shots do hit someone, the paint doesn't break.
4. Squegeeing is a royal pain at best, and if you don't do it then the barrel is even more useless than before.
Those points speak for themselves pretty much, and are readily visible upon any occasion where you see them in use. The Flatline is so named for the brainwave pattern of those who buy/believe in them. Ask virtually anyone else that pays attention on the field and they'll say exactly the same thing.