Myself and two others are considering providing short term loan.

A group in my area is flipping a million dollar home.  They have put quite a bit of rehab into it and our out of funds,  They are asking for a 50-100K 6 month loan and are offering generous interest.

Myself and two other personal investors want to commingle our funds for the loan and share in the interest on a proportional basis.  

Want type of corporate entity should I set up...llc, s corp, partnership?

What language should I look for on contract to secure my money? I'm thinking lien/where I stand in repayment order of other investors.

Any help would be greatly appreciated.  

Thanks,