The new design takes the home from a 3 bed, 2 bath to a 4 bed, 3 bath, 2,400 sq ft rambler on a large lot in highly desired area.

While may not have high amount minimums, they may have a minimum $ threshold for cc processing, Ours is $0.60, with a discounted plan that could be a few as 8 records.

I want to go the buy-and-hold route, and I am interested in finding a duplex that will provide a steady cash flow, a high appreciation value and does not need renovations.

TLDR: I don't see a reason for small landlords to use concessions - either the price is too high or you need a remodel if your unit isn't renting.

That looks to me like $200-300 too high for the current rental market.

If you start a JV in name but do not give your partners proper control and decision-making rights and the deal goes bad you open yourself up to serious consequences which can lead to SEC violations with extremely high fines.Lastly, you can offer the project up to investors who have no voting or control.  

Based on your numbers, and assuming you have a credit score high enough and have never filed for BK, you shouldn't have an issue getting approved for an HML to buy/rehab the property that I would estimate at about $370k-$375k (which includes 100% of the rehab costs).

I'd highly recommend Scott Kind, CPA - 518.461.1699.

Our goal is to keep your maintenance costs low to keep your return on investment high. 

He is a BP member and comes highly recommended by many here.