I don't know of a shop for you but the math on your economics doesn't really work well. You're saying that you can earn 5% a month and want 80-90% for yourself. So if I'm your prop shop, I earn 10-20% of the 5% = which is about 6-12% a year. In return, I need to backstop your strategy which includes being short options. If another Global Financial Crisis spikes vol, I run the risk of losing more than the $450k I put up as collateral if the short options positions skyrocket and need to have faith that your hedging is good.
I don't know of anyone willing to collateralize an options short selling strategy where their best-case ROC is 10%/year. There's a reason that hedge funds are 2/20 and not 0/90 -- I suspect that if you find someone who'd be willing to accept a 50-50 profit split, you should jump on the opportunity.