I am currently seeking equity partners and/or personal loans as viable options. 

Another option is to get a quote so you at least have an idea....and if something happens in the next 12 months for example, and you are okay with the quote, you can just reach out to the person to do the job he/she quoted.

But it is one of many options I’m trying to come up with.

You will then have a few options with that rent money....you can put it into principal or you can start saving it to purchase yet another property.

I have long been weighing the option of acquiring an MBA as it seems to be the most practical real world degree for someone developing their business acumen and career.

What are some different options to get about $300k for for the construction which should take less than 6 months to complete and get the refi?

They are both good options, although I would say that Columbus is a bit overrun with investors, even though you can still grow there. 

I hope this helps you think through the options

Open to potentially purchasing in all 2-3 locations simultaneously, depending on options.

The site I used made it easy to compare local quotes and find affordable options without compromising on quality.