When bringing up subject-to as an option, the agent kept stating that his loan was un-assumable and that there was nothing more outside of traditional financing that could be done.

It was just a way to earn a few extra bucks when the circumstances proved right.The same for subject to deals; loan subordination; purchasing of “discounted” notes, or hard money lending.  

@Ernesto Miguel CreditoMost BRRRR investors will finance with a hard money loan and refinance into a DSCR loan. 

I haven't read any books or even online blogs.

We have a company that buys Non-Performing Loans and, as a secured creditor, we love seeing BK paperwork.

I received an offer for 100% purchase and 100% rehad on a fix and flip from Blue Pacific Home Loans.

I have good personal credit (~730-740), average-high personal debt (mortgage, student loans, vehicles,) and I am employed making $90k/year.

Run through some of the features you will need like setting up a property, moving in a tenant, receiving rent payments, and publishing online applications and see which one works the best for you. 

Additionally this hard money lender is at 75% loan to value are there any lenders offering 80%?

I did a 7.5% down conventional loan.