Any suggestions for digital to analog cards?
running Fedora 8 and Ardour 2.1

Depends on your budget and your need in term of number of in- and outputs.

M-AUDIO Delta series is usually recommended as a budget alternative with guaranteed low latency that’s rock solid under GNU/Linux with JACK. They have been around a couple of years so it’s very likely you can find used interfaces at very low prices.

If you want to use FireWire then you should check out FFADO (formerly FreeBoB) list of compatible audio interfaces.

And if you have some money to spend (and want lots of in/outputs) then RME Hammerfall 9652 with external A/D-D/A boxes the way to go.

Thank you