KhanFire:
I have been playing scenario for 3+ years now...Team Captain of a team, played sniper, been a referee on many ocassions...in short, been there and got a hickie there too. All players on my team have Tippmann 98's. The new custom can be had for about $125.00. This will leave money in your budget for a tank, squegee, remote line, mask, and fanny pack plus some loaders. I have one player with a flatline.
The flatline will shoot longer than any other gun, but is NOT terribly consistent from shot to shot. Put 12" Smart Parts All American barrel on it and it will be very accurate for close up work. (Actual tests have been done and this is the best barrel for the gun.)
Be sure to get a fog-proof lens in your mask as well. A must have. Oh, and some cheap gloves are good as well.
Almost my entire team of 12 have purchased their equipment at www.888paintball.com.
If you have any specific questions, let me know.
-White Horse