Since we will not be doing the work until later on, would it make more sense to use the 504 to purchase the property only right now, then seek another loan or LOC when we are ready to begin the work?

@Joseph Chiofalo has some great nationwide STR investment loan products and fixed rate second/Helocs for investors loans clients tapped into recently. 

I would love to find another Fountain square back east and start doing infill like this article maybe 1 to 2  month would  be great we would just use cash so no loans etc..

How long it takes to be financially ready is different for everyone.

The client cup of tea is loan assumptions with value add.

The financial model presented seems overly pessimistic.

If using high LTV loan and legit underwriting, the purchase will have negative initial cash flow.  

Sec. 1.469-5T(f)(2)(ii)) – such hours include: studying and reviewing financial statements, searching for new properties, education, preparing summaries of the finances or operations, or managing the finances of an activity in a nonmanagerial capacity.Keep in mind that REPS can include a real estate agent and tasks that count can be different than a real estate investor....

What's your long-term financial goals?

However just know that you wont be eligible for most residential loans if you decide to put it under an LLC assuming your needing funding.