Also any advice on how to lower the tax on my flips. 

DTIs do not apply, not tax return / personal income eval

30 year fixed, low interest rate DSCR BLANKET loans (put multiple 1-4 unit properties under one loan for cash out or for purchase).Ground Up Construction loans for aspiring developers with NO Experience100% Financing on Fix and Flips (just pay closing costs and prepaid taxes/insurance)Fix and Flip financing that requires no appraisalHELOCS on investment propertiesBuilder's Forwards (for medium to larger developers who want to hedge interest rates on their properties they plan to sell so they can offer "low builders rates").DSCR loans for long term AND short term rentals (I think this is becoming more and more common, but some people have still never heard of this).And so much more!  

Capital stack is usually a term used on large assets for the order of priority from debt, mezz, pref and common equity.Are they basically a hard money lender?

I can sell the units hopefully for about 840,000 before realtor fees of 5 percent and whatever I'll be taxed on.

Seller financing does not always sell for more money and if there are big price declines then you may end up having to forecloseMy recommendation is to sell it with borrower getting traditional financing and put that $ in a tax friendlier account than loan interest = ordinary income rates

I live abroad in Bermuda and I'm currently unable to buy property there due to restrictions and transaction taxes.

Basically trying to get the most tax benefits and protection as possible.

Tax deductible improvements such as drainage tile, terracing, irrigation can significantly improve the productivity and the value of the land.

To sum up the risks to the seller; the seller remains liable on a note which is secured by real estate they no longer own; the property sale has violated the due on sale clause of the mortgage or deed of trust and the note can be accelerated by the lender; the seller’s credit capacity is impaired because he has debt with no offsetting property equity.