I decided to go with conventional financing for the same reasons you laid out, however I would ask why the FHA interest rate is so much less than conventional. 

If they were close to your $39k & 145k actuals, you could have predicted a loss from the start from just a rule-of-thumb:($92k+$39k)/$145k=90%Here, the conventional wisdom says this shouldn't be more than about 70% to 75% or so to make a fair return.

They will give you conventional 30 year term up until 10 financed properties and then you can use their Portfolio Loan product.  

Source of FundingI plan to start out with conventional loans.

You of course are required to use licensed contractorsI did this when I built my house.For financing purposes if you are using conventional lending the bank will require a licensed general contractor and will not let the owner act as the GC without a license - but this is a lending requirement and not a county requirementWhat county is this in ?

In regards to acquiring properties, I'll be financing the first property through a conventional 30 year fixed loan with a 4% interest rate.

Personally I had the best success with properties that needed rehab, so they weren't moving with a standard sale because conventional lenders wouldn't finance it.  

Regardless, the 55k loan is at 8.5% interest only until its occupied which should be August 1st which at that time, I will refinance into a conventional 20-30 year loan. 

It's an estate sale, and the seller was very short with me on the phone but here's the info he sent me:Estate sale - House + lot with potential to be subdivided (could profit from subdividing and selling the land)Looks like a single family home, I'd guess 2-3 beds/1-2 bath. 1.33 Acres (57, 935 Sq Ft)Asking $250kThe "county listed it at $238k"Conventional financing only.Description on flyer: "beautiful lot with large trees, quiet neighborhood, newer larger homes in the area.

i.e. http://www.housingfinance.com/Are there government incentives over the conventional construction process?