I'd probably get multiple feasibility studies before engaging a bank and/or spending any money on the actual project.

Many property owners in this financial situation do not know who to trust since they're being told different things by attorneys, the bank, investors, and Realtors.

Please help me find a bank, credit union, etc that will let me use 100% of my equity on an investment property for an interest only HELOC.

I met the bank appraiser during his visit, and he shook his head at my purchase price in amazement.A year later, a duplex, now valued at $240K was advertised in the papers for $180K, also by an agent.

Local banks and credit unions will be the best place to check for this.As for the strategy, using a Heloc for the downpayment will get you into the deal, but how do you plan to get out of it if this is a long-term hold?

I have some soft quotes for bank debt but I'd prefer to stick with private debt if possible. 

I combined owner financing with private money and then refinance with my bank.

There are banks out there that offer lines of credit for GP stakes, which many established syndicators utilize and draw on to potentially fund their follow-on offerings.  

Take the check to OUR company's bank and show them the POA and any other supporting documentation.3.

This means you have the tenants provide you their bank info and consent to auto draft and you draft rent from your side.