Knuck this might be a little late to suggest, but I had the 98 with a Flatline for about a year and a half. All I have to say about the Flatline is that it is accurate, but it merely lobs the paint rather than actually firing it after about a good 200Ft.
What I suggest is just to get a JJ Ceramic Barrel off of this website.
First Call Paintball, Paintball Loaders, Tanks, Marker Guns, Paintballs, Paintball Gear - First Call Paintball
The last time I checked I believe the barrel was going for about $30. I know the barrel is a bit old, but it cleans the barrel out after every shot. It is also very accurate and can come in many different sizes.
So if you really want that punch while taking that shot, rather than having a barrel that has more distance, yet less power then this is the way to go.
DAM I JUST SOUNDED LIKE A USED CAR SALES MAN!!!!!!!