How to best build a rental portfolio using cash (not borrowing) ?

[Flue Hasipi]

Right off the bet, the reason I don't want to borrow is that dealing with interest is against my religious beliefs. I am preparing to move to Tampa Bay in 3-4 months, I will be renting for a while so I can use my $350K -$400K in cash to invest. My plan is to hopefully get into flipping and once I have made some extra capital to buy a property for cash and hold it, then hopefully repeat. I could possibly sell my rentals in AK and free up another $350K if I realize that I am able to deploy it and make more than the $4K monthly cash flow it now brings. Do you recommend another strategy to aside from flipping houses that would help in building a portfolio of cash-flowing properties? Would a STR be a feasible alternative in Tampa Bay?