Since you want to aggressively invest in the near future, you will need cash and the 30 year option is the right one for you.

I fell off the wagon when I saw a bullet point that indicated all second story apartments have an elevator and their suggestion that it was possible to get 1000% Plus Potential Cash-on-Cash return in the 1st Year.Where has SCDC built?

The capital required for Denver, and limited cash flow makes it a tough market to get your next one.

If he owes a decent amount on the property, wouldnt the conventional route make him lose whatever interest rate he has?

I imagine you also ensure the amount you're lending is less than the ARV of the property.

Mortgage lenders will qualify you for a higher purchase amount for multis than they would on a single, because they will count the rent you will be making on the other units as additional qualifying income for your loan application.

@Samuel Coronado - cash flow on new builds here right now is fairly non-existant without putting more than 20% down. 

We would buy this house all cash. 

Harder to cash flow due to 25yr am vs 30yr standard.

Then you can read a more in-depth book like The Book On Rental Property Investing by Brandon Turner or The Unofficial Guide to Real Estate Investing by Spencer Strauss.Here's a guide that teaches you how to analyze a property.https://www.biggerpockets.com/blog/rental-property-cash-flow...Finding deal that cash flow is the easy part.