macdaddy007 - Ignore the previous replies to this thread. Their advice will save you a little money, but it's only
delaying cost. The BKO is an electro-pneumatic ram-valve marker (the same cycling system that most high-end guns use), whereas the Imagine and other spyder clones are blow-back's (meaning the bolt is forced back by air pressure after firing). There's nothing wrong with a TES or Imagine, but it sounds like you've played enough already to know that you're likely to stick with the game. I say pay a little more now for a better gun and save yourself the cost of an upgrade in 6 months.
While you can run a BKO on co2, again, I suggest you "bite the bullet" and get an HPA tank now. Almost everyone gets HPA eventually, and odds are if you get into the tourney scene (or just get a high-end marker), your next marker isn't going to run on co2. The choice between a steel or fiber tank comes down to:
1) How much are you willing to spend?
2) Will the weight difference (steel tanks are heavier) bother you?
Keep in mind that steel tanks are becoming less common these days, as fiber-wrapped tanks offer a lot of advantages. Also, fiber tanks are SLIGHTLY less durable, but if you're beating your tank against concrete, you shouldn't be playing paintball anyway.
