Where can I find a list of paintball guns that are possible to run HPA stock. Or list them please...?

Most if not all Paintball gun can use Hpa stock . Newer makers are made to use both Cos tanks and HPA (like the Spyder Electra)

every paintball gun can use an HPA tank. however not every paintball gun can use co2. this is because of the reg and o-rings etc..etc..

but 250 for a marker? hmm..if you're talking brand new?

smart parts ion

indian creek promaster

kingman vs3

smart parts impulse

evil omen 2.0

these are just a few off the top of my head

those are ALL electro-pneumatic markers. i'm assuming you're not too savvy on the whole paintball thing. think about the super expensive 1500 paintball guns you see pro players use on tv. the one's i listed will shoot somewhat similar to those. the spyder you mentioned (like all spyders and tippmans) are blow-back guns that will shoot like a junk in comparison.

Almost all paintball games can run on hpa because it does not freeze o rings like co2 does you can also check pbreview.com for more info.