if you want something realiable and speedy, by all means go with the Tyan boards. I wouldn't even consider anything else now that I've used them. Every other damn dual board I've used has had issues, or just plain sucked. Tyan's just seem to work, although they are finicky when it comes to RAM.
If your workstations need SCSI+ethernet, go for like a Tyan Thunderbolt or something. Either that or the Tiger 133 should be rather nice.
-Phil