Generally you would do an allocation of your purchase price to the land and building portion based on the allocation done by the county property appraiser.As to your question about hiring a CPA, I am probably biased as I am a CPA, but I think ultimately you need to do what's best for you.

I calculate that with $250 per month allocated towards repairs and CapEx, $100 per month for vacancy, the $590 per month in utilities insurance and taxes, and about $160 for a mortgage payment ($25,600 at 6%), I would still cash flow almost $300 per month.

But maybe I'm just talking to the wrong providers and of course in a Los Angeles and San Francisco context where naturally more basis would be allocated to nondepreciable land than in other locales. 

Rather than have your retirement savings entirely allocated to equities, you can choose to hold a rental property in your IRA or have your IRA lend money to other investors.

This logic is difficult for me to digest given this is mid-year and all the funds are allocated previous year.Anyone with experience or insights?

That was was my exact plan in regards to the multifamily in regards to the allocation of units but I did not know about the 203k until @Casey Murray mentioned it so now I have a much wider array of options purchase-wise.In your experience, is it worth trying to assemble an estimate based off of market rates and building specifications or should I just wait until I get the estimate from the general contractor?

The benefit here is two-fold: (a) it outlines all functions and components necessary to complete a site-built structure from the ground up; (b) you have a clear template for allocating responsibilities on rehabs.

Do you mean 30-40% of the tax basis, after land allocation?

You can allocate your proceeds any way you like. 

Since I have not yet obtained a private loan on a property and dont understand it's mechanics, I have a question on a specific scenario I have been playing with: If a private loan is obtained and the down payment is payed for using a cash advance on a business line of credit, could you then turn around and do a cash out refi with a conventional loan, and specifically allocate that money so that you can pay off the business credit money and a large chunk of the private loan?