Use Solo401k or conventional loan to buy investment property?

[Shelly P.]

I need some advice from BP.

Situation:  I have opportunity to purchase an investment property - around 320K with equity of about 100k.  I have two options;

(1) refinance and take out cash against another house with about 700k equity and use to purchase the house

or

(2) use my solo401k to purchase the property with 20% down and get financing

What is my best option?  What would you do