How to combine 2 loans?

[Taras Kokhman]

Hey everyone! I came across a valuable deal in Miami, FL. Its nice cash flowing 5 unit commercial building that is fully occupied and has about 6k income a month. The rents are below market price, so we can do minor renovations, increase rent to about 7.5k a month and increase property value.

The seller accepted our offer of 800k and willing to finance 500k for 5 years. We are looking to finance other 300k to make a purchase. The end goal is to fix up the property, increase value and refinance within 1-2 years and hold it. 
What are the beat ways to finance remaining 300k ? Thank you