I would recommend speaking to an attorney of course, but there are several options. You could get private money from friends, family, or other interested investors. Although, for it to be your primary residence you are not really showing an option to acheive returns. You could offer terms that involve owner financing. That would be where the owner is collecting your payment as if he was the bank. You could also setup a lease option with the owner where you are renting and your rent payments accumulate as part of the down payment or purchase of the home, if you execute the option within the alotted timeframe agreed upon. The latter two cases would require that the owner is able to under their current mortgage and that the bank does not initiate the due-on-sale clause that is usually found in their terms.
There are a few ways to make this happen. However, purchasing a home as your primary residence without a potential ROI for others to include their funds is not going to be very attractive. Lastly, you could always use cash and pay the full price to the owner. You could potentially negotiate a great deal because of the power cash has. Good luck to you and I look forward to seeing how you make this happen.