When doing the input in the Wholesaling Rental calculator should I base the loan on the ARV (as the calculator suggests) or on what the property owner is asking.

I suggest you calculate IRR of the investment in two scenarios with all other variables held constant except loan paydown (i.e. the variable you're interested in).

@Stephanie PotterThank you for the suggestion. 

I'd suggest that if you are going to pursue this strategy that you focus your efforts on figuring out who you might want to invest with, conduct thorough due diligence on them, talk to references, and visit their offices...and invest with those groups directly rather than through a crowdfunding website.  

I'm not suggesting one way or other.

The reason I suggest that for you is that it would allow you to get into a deal for very low money down...you could even use a VA loan for nothing down and have a huge reserve.

Within a couple of hours of getting the ticket, I had his suggested measures in place.  

If you have that kind of cash available, I’d suggest looking at other markets and put %25 down.

I want to get a book or suggest a course about Real Estate tax law for my brother that is a tax attorney.Ideally something about taxes on small duplex/triplex investments, rehabs, depreciation, etc., and how to maximize savings and write offs. 

Its a highly regulated industry - I would suggest you consider just finding a brokerage that will work with you - there are many.