You would be hard-pressed to find the same flexibility with a bank.Cons;1.

If you are a QREP (qualified real estate professional), you will have more flexibility matching your losses and gains. 

Commercial/portfolio lenders often prefer it in an LLC, but those are more flexible and more expensive usually.4) Do you get each LLC insured or is there a umbrella policy?

If so, you can always just make extra payments to principal and still have it paid off in 15 years, BUT you would also then have the flexibility to NOT pay the 15 year payment amount (vs 30 yr amount) if times got tight, AND when it comes to financing your next property, they'll calculate your DTI based of your minimum required payments, in which case you want the lower 30 year payment to show on your credit vs the higher 15 year minimum payment.

If I do the HELOC, I might end up paying more later on, however I'll save on the rental payment being lower and have more flexibility .Anything I'm not aware of or perspective you see which might help? 

I'm sure there are others who will have a different opinion.Going back to the beginning of my post, if you do have a strong income and deep pockets you will likely have more flexibility to make mistakes without significant risk to your overall financial health...but I'd still recommend starting relatively small.

There might be a few out there who don't require it, but private money is typically more flexible on that end.

And buying opportunities for those with flexibility and cash is pretty darn good.

The best I got was 15%, and that was pretty good.A few thoughts:Have you talked to your dad and uncle to see if they would be flexible on pricing?

Much more flexibility since the portfolio loans are kept on their books.