Welcome to WebmasterWorld Guest from 184.108.40.206
So my question is what one do I setup and use as the real domain name for inbound links and the such.
I don't see any reason to use the one with the dash at all. Let it expire and save some money.
That's sure not the advice I'd give!
Ten bucks a year to register an extra domain is cheap insurance to protect your brand and keep it out of the hands of copycat competitors or squatters.