Originally Posted by Gibbs
Unless you can get a 232 really cheap and you live very close to a dive shop (for air) then your better off spending that little bit more for a 300.
They stay in test for 5 years, so make sure the one you buy is in test or cheap enough to justify the cost of a test. (Don't buy a carbon bottle, they are being phased out due to safety worries)
Make sure you buy a bottle with a built in surface only guage. Not all shops, but a growing amount are saying that if a bottle can be used underwater then they must be subject to that testing and therefore will want a test every 2 years, or they won't fill it.
It's not a big deal to get a retest, and an airgun bottle has an easier life, but it's a small cost and a hassle.