If so, what happens when a due on sales clause is initiated by the bank?

Save for 7-8 months and get my 20% down of 10k on it and go to a bank which isn't my favorite option or maybe since I was reading on here that life insurance company's have a very low interest rate and like to invest in multi family buildings that would be another good option.

Conventional loans are offered by nearly every bank and sometimes they are the only loans a bank may offer....but there are other loan types.  

Either way, after that year, banks will be able to truest you since you'll be able to show you successfully managed a rental property.

Hi,I'm looking for banks that allows to buy an investment property through a HELOC.

A HELOC will require you to call around to a lot of banks.  

In general smaller local banks and credit unions are more likely to do manual underwriting than big national banks.

Commercial lenders from smaller banks will be willing to think outside the box if the numbers work.  

When borrowers get behind the bank sends a rep to check the property.  

A couple of months ago I was fortunate enough to come across a meet up hosted by @Katie Pratt and @Merced F. where I learned about this amazing community.