Investment partner for down payment / closing costs?

[SD Young]

Aloha, 

New to HML and PML. Looking to purchase a multifamily building in town. Owner and I very close to finalizing the terms of a balloon, interest-only purchase agreement. I have funds tied up through 401k / retirement account at work sufficient to cover the agreed upon down payment and some closing costs (close to $100k). Obviously, I'd rather not liquidate those funds early but am prepared to do so for this deal, as the property has value add potential and cash flow. But I would need a few months to liquidate and season the funds and the owner wants a quicker closing. Will be tapped out in the short-term after earnest money, inspection, etc.

 Recommendations?