Combining Private money lending and HELOC

[Bogdan Petrovic]

My first time posting here but hopefully I will get some good answers,

I found an off market deal [SFH 3/1 with an additional dwelling unit, rented for $1500 + $900, priced at $275k]. My income is not sufficient and I would never be able to get conventional financing, however I found a Private Money lender who would borrow me 75% of purchase price with 24 month balloon payments. I still need to come up with the rest of close to $50k after I put some of my savings towards. Please help??
Could I get another personal loan or how do I structure this deal?