I'm conducting research here in New England for firms that facilitate MHP residents purchase their Mobile Home Park and transforming the park into a 'Resident Owned Community'. 

You are telling us you, who run a brokerage that presumably helps facilitate the sale a real estate, and your partner, who is licensed by some state to help facilitate the sale of aforementioned real estate, don't know that you can't sell a property that you only own 1/4 of without the folks who own the other 3/4's consent?

Does anyone know a private lender, local bank, or credit union that can facilitate these transactions with reasonable fees?

Your DST sponser would have to facilitate the transaction though. 

Are you already in contact with a realtor or building your team to facilitate this process for you?

If you want checkbook control, a self-directed IRA will involve a setup fee from the custodian (a registered bank or trust company required for IRAs), as well as a setup fee to the LLC facilitator for their service, a formation fee to the Secretary of State in the area you choose to form, annual or quarterly fees to the custodian, and annual fees to the Secretary of State.

A trust will, however, facilitate the ownership transfer by avoiding probate, which depending on the state you're in, the value of the estate and a few other things can be a short or very long process and expensive.

My questions are, does anyone know where to get a good Ma wholesale/assigner contract and does anyone know of a Worcester area real estate attorney who could facilitate executing those contracts?

They are an online solutions provider for landlords and ACH facilitation is one of their services.

I can also facilitate hard money lending in-house and will handle the refinance process for you.