I need creative financing suggestions

[Ron Averill]

I'm currently in negotiations for an off-market deal involving four houses. These will be buy-and-hold properties. The seller is retiring from the business. The total selling price will be below the total of the current mortgages on the properties, so the seller will have to bring money to the closing.

I would like to find a creative financing approach that would (1) help the seller to bring less money to the table or to spread out this cost, and (2) delay my need for conventional mortgage(s) until I complete the rehab work. 

Is this a good candidate for a wrap? I don't have any experience with creative financing, but I've read some impressive concepts here on BP, so I'm hoping someone will have ideas for this situation.

Suggestions?