[jerf]

"Inflatable" doesn't have to mean "tightly stretched rubber like a balloon" or "lowest bidder plastic heat-bonded together with a picture of a flamingo in it". You can build strong materials that will still inflate, especially with .5-1 atmospheres of pressure, no problem.

[zardo]

I'm pretty sure everyone is using a standard pressure and composition on their spacecrafts and stations now. If you want to dock with existing craft and not have managing atmospheres be a big problem, you want to stick to the standard.