I am using a a similar technique to flip homes. As soon as I find the deal, they put up the cash at escrow to buy the property, I secure my interest with an option and 1st trust deed mortgage. They put the monies in escrow for all the repairs, or open a seperate account with online access for all parties in the deal. I do all the dirty work and all parties split the profits 50/50. I just finished one today and will be ready to sell it this week.
Jack said once that 50/50 is fair for all the time spent finding the deal, managing repairs, selling for profit and your time into the deal. This is just one avenue that you can use. Also, FHA just lifted the 90 dat seasoning rule!