There's no reason you can't use the push-button sling swivel that came with the kit. That's what it's for. Some operators don't like them, however, since they have been known to pop out at critical moments. Or so I'm told.
Also, since our adapter looks just like an AR-15 in the back, you can go ahead and use one of those GG&G end-plate sling loops for AR-15s, such as the ones you illustrated.
Finally, because the threads in our mount points are 10-32, you can also screw an Uncle Mike's machine screw sling swivel stud into any of the (unused) holes.
In a month or so we wil have stamped steel sling loops and hook loops for attaching to our mount points. These would be similar to the GG&G loops you pictured, except they would be specialized for our adapters. You might have seen one at the gun show. Real heavy duty stuff for people who don't like any of the other sling solutions.