The answer to your questions are "No, No, and Yes".

There isn't a ARC or AlphaBIOS f/w support. And probably won't
be for quite a while.

Also, there's no PCI IDE support yet, so the PC164 IDE chips
aren't seen yet. And I've stopped trying to commit to finishing
things I don't seem to be able to get to yet! :-<

However, you *can* get SRM for the AlphaPC164, and I've found
the board to be quite nice. I've been running off a system
I purchased from Aspen Systems for some months now and have
had no problems with it.

Your tricky problem is that you have to get a mass storage
controller that the SRM will understand. I happen to use
a Qlogic 1040. Curt Sampson or others have mentioned using
other PCI controllers.

-matt