After visiting the property and meeting with the wholesaler and my mentor I was told to be that I needed to buy the contract from the wholesaler with a down payment of $2000.00 (non-refundable).

It's a non profit organization, most REI clubs are not.No sales, just education and networking.

I know that in order to get leverage in a SD-IRA it must be a non-recourse loan.  

As a residence, that won't appraise out, (1.) there is too much value in the greenhouse attached than to the residence (2.) won't be getting a market approach on a 1 bedroom or with the greenhouse (3.) it's not common for the area (4.) the highest and best use probably isn't residential (5.) marketing time on an appraisal can't be established......there is just a list of appraisal aspects with non-conforming properties. 

My reasoning is pretty easy to follow- 1) Many of the rest of the world's central banks are lowering rates in fact some are going negative.  2) Inflation is currently a non-factor and is expected to be until 2018 given the continuing rout in commodity prices I don't see that turning around any time soon. 3) Labor participation rates are at long term lows.  

While it is still against federal law, enforcement by local authorities is non existent.

To overcome this obstacle, you may want to look for a non performing building with a motivated seller.

how big a loan for a mobile home park should be to be the non-recourse loan? 

Being a friend to walk through a house you want to buy and seeing if it fits your needs sounds like a non issue.

Non-occupying Co-borrower - A non-occupying co-borrower on an existing FHA-insured mortgage may qualify for an FHA-insured mortgage on a new property to be their own primary residence.