Building a marketplace is hard. You'd want to prove that you are capable of being scrappy and still build a community. Once you've got that, then you will have a better pick of developers because at least you have some proof of traction.
Look for some of the PHP marketplace scripts. Actually, Dating is a typical marketplace (for people). If you have design skills, you can replace the graphics and text and you should have a semblance of a starter site rather quickly.
Whatever you do, only offer equity on the basis of people delivering working code. Otherwise, you'd have a ton of free lodgers.