If you're looking to a rent with an option to buy because you can't buy now, make sure you really understand what you're getting involved in.
While you and the seller are free to come up with any kind of creative contract...........In a traditional rent w/ option to buy - there is some non-refundable option money given the seller in the event you, the buyer, don't exercise your "option" to buy.
The seller must sell at the agreed upon price, but the buyer doesn't have to buy............that's why the seller is given the non refundable money.
This may be in the form up an upfront deposit.......or an amount paid monthly over and above the normal rent which would then be applied to the sale price should you buy at the end of the lease term. If you don't buy the home, that additional money may be forfeited
My problem with this is....if you can't qualify NOW - you better make sure whatever issues you have will be cleared up, and you will qualify when the time comes, or you won't be able to proceed.
As Ron mentioned, the sale price is usually decided NOW.......in this market I wouldn't want to come up with a sale price for a year from now........besides, you don't know what the mortgage rates will be then, either.
I suggest you rent and save your money for the down payment, and then see where you stand at the end of your lease.........if the seller wants to sell, and you CAN buy, then strike a deal at that time.
Just my opinion.........Whatever you do, I advise you to make sure a real estate attorney looks over any contract before you sign it.