From experience, I would say don't put ANYTHING else on the same NT server as Domino. What release of Domino are you talking about, and what features?
I've seen a Domino server that was also running SQL and it was really pathetic. P3, 512MB RAM, SCSI RAID5, slowed down to a CRAWL.
That's my opinion, of course, so somebody else who's worked with Domino might have a more positive take on this.