I recommend googling rent to own homes and you will find some great articles. I also like
Realty Times - Real Estate News and Advice, put rent to own in the search and many articles will come up. usually, you will need to pay over market price for your montly rent. Anything over the market is earmarked for your downpayment amount. it must be structured so that the mortgage company can see what you have paid into it and can truly be attributed to over market rental so it can be counted.
And you purchase some time in the future at an agreed to price now.
Why not just rent and save your own money in your savings account and earn interest on your money?
And no, I don't know of any tax advantages for you. BUT, I am not an accountant, nor do I play one on TV, so you would need to check that.
Shelly