Well, I might have some good news, but not really good.
The Zoom has some hope:
Zoom Telephonics: ADSL X3
Zoom seems to be trying to update their drivers. You may just want to look here often. It might serve as encouragement to them if you shoot them an email asking for those drivers (nicely, and with the understanding that they may not be ready).
The Asus is going to be a no go. They haven't made a driver for it since 2004, so your chances aren't good. You could try the 32-bit one, but it's not likely to work.
That's the trouble with 64-bit. It's stable, but we're losing some support for legacy products. I guess the idea is to move forward, so that's just a by-product.