Sorry for the necro-posting, only spotted this thread...
There are quite a few PCI sound cards that work OK under DOS, I found a SB variant with an onboard amp and output it to the AR board in my Asteroids Deluxe. I'll dig out the model no. later if you still need it, there were a good few on Ebay when I got it and it only cost me £1 or so.
The linux port works but needs a ZVG code rewrite really. I got the menu working without too many changes after squashing some bugs in the ZVG SDK, but you can't hit the hardware as in DOS so it needs SDL or SVGALib or similar to handle input etc. I was waiting on Steve settling on a flavour for the rewritten Linux version and was going to use the same. I may crack on anyway... had the thought of trapping the ZVG vector calls and writing them to screen as well/instead which would make development a whole lot easier...
There's a slightly updated DOS menu with a few more manufacturer logos in which isn't released - I may slip a link on here later for those who want a beta look.
You should be OK to use it in a Tempest cab (hopefully) as the menu supports rotation and spinners, though I don't know anyone that's tried yet.
Cheers,
Chad