which wd hitch?

I am looking to buy a toy hauler.I had a 27 footer and I sold the wd hitch with it. The one I am looking at now is a 21 foot, 5,000 pounds dry with under 1,000 hitch weight. I have a 2008 3/4 ton duramax.

Can someone please show me a couple ideas on which hitch to buy online? I don't want to pay the $500 from a dealer.

Thanks!!