Seems a lot of sellers are taking advantage of the hot market right now.

So, please keep all of this background in mind and take what I tell you with a grain of salt.To me, given the amount of money you and your grandparents are going to invest into this new construction project, the ROI seems very thin. 

. $1250 seems a bit low for the main line TBH.

Prices are very high and cant find a deal for investment so it seems like utilizing my Va home loan and move every year or two and be able to rent the other one is my best route to start my investing career.

If done properly, they'll give you max value long term.You seem to be doing things right. 

Seems to be an equitable structure and they delivery a nice product. 

However, if I find a property that I really want to purchase any advice from those in the Phoenix area on which HOAs are more stringent on their CC&Rs as opposed which seem to provide more leniency & flexibility? 

Google search Sell Jacksonville House Fast and call the first few people that show up organically and as paid ads that seem to be local.  

Neither option seems to take advantage of the market conditions.

As long as you are frugal and complete your due diligence and a good portion of the leg work (as it seems you are doing), the overall costs of the development wouldn't be outrageous in comparison to a comparable existing park.