Tarek El Moussa Down to Do New Show with Fiancee Heather Ray Young

Tarek El Moussa is a glutton for punishment -- at least that's what HE joked as he revealed he'd love to work side-by-side with wife-to-be, Heather Rae Young. The "Flipping 101" star joined "TMZ Live" Thursday, and said, yeah ... he's down to walk…