You should be fine, unless your ultra ata is an add in card. Then you
may need to check and see if it is supported.
I have heard some reports that older K6 200Mhz chips had a few bugs in
them when they tried to run Free BSD. While I haven't been able to get
AMD to confirm this, apparently AMD fixed that problem in the chip. You
should be fine, everything else looks golden.
SIncerely,
Benjamin L. Backus