Having owned 2 properties in the past and currently owning a SFH as well as a current business owner I can judge most rehab prices pretty well and can form budgets as well as project manage. 

I had a budget, and 5 bdrm/3 bth was the "secret sauce" to increase my margins.

Find out the age of the systems (roof, HVAC, Plumbing, Windows, Hot water heater) this will help you determine capex budget.

Get rid of debt, build a budget, and save.

.$40,000 Purchase Price$20,000 Rehab Budget$100,000 ARVThe initial terms are going to depend on your credit, experience, and liquidity. 

Beyond that, with regards to book keeping, I would wait until your time deems or budget allows for a book keeper. 

Originally, I was looking for FHA loan, but when I found a 5-unit building within my budget, they told me that FHA doesn't work for that because I need a commercial loan for anything over 5-Units. 

You need to tighten up your budget and work on getting your HELOC paid down.Without knowing your whole financial picture it is impossible to answer other than pay down the HELOC.

If you can't afford that, then I recommend you focus on increasing income, budgeting, and saving.

That is only 28,000 plus closing costs, well under your budget of 65k liquid to spend.