Looks like a nice card, are you just supposed to use 2 of the 4 "outs" to a monitor system or what? Doesn't appear to have any connections at all besides the 8 jacks.
Or use the mixer in your monitoring chain, if you're picking up a separate preamp. The Behringers are certainly fine for that. I think the Omni thing is a bit limiting for future expansion (although good for what it is). The other outs on the Delta give you options for signal routing if you have outboard processors or recorders.