Since the emergence of the g ads threshold methods publicly, seeing a few of these JV threads lately, but OP have you already run any campaigns yourself? If yes, providing more info on how well your accounts have performed would help people decide on if they want to do JV with you. Cos, the suspension rate could be high and there might be waste of time for both you and your partner.
How about running them yourself for a few campaigns, good or bad (I mean you make profit or loss, you get the chance to test them and show the world that they work), and show the spend rate of your accounts?