which unix to run on a 386/486 machine

[Henry Minsky]

I am working on specifying a dedicated communications controller
node which we want to base on an AT 386 or 486 platform. Can anyone
give me recommendations on which is the best UNIX system to run for
doing multitasking and possibly some realtime communications.

I am considering SCO Xenix and Interactive as alternatives. ARe there
any others which people like? 

Thanks,
	Henry Minsky