Loan Now or Wait for All Cash Deal?

[Dung Tran]

For my first home I wanted to start small so my goal was 100k for a 3 bed/2 bath home so I can live there as my primary residence and be able to rent the other two rooms and essentially live without paying for mortgage out of pocket. Small chance of positive cash flow . It's doable but in my location homes in that budget aren't as plentiful as they would be in other cities/states.

My current situation is that I'm currently living with my parents so I can save up money for my first house. I'm currently in a position where I can comfortable pay a 20% deposit on the house and take a loan out for the rest. I'm currently debating on whether or not I should take a 15 year, 30 year loan, or just wait another 3 years so I would be in a position to buy a house all in cash

General estimation of a 30 year mortgage @4% APR would mean I'd have to pay around $57,500 in interest according to a basic mortgage calculator. There would be a small positive cash flow though. .
The pro to this is that I can get a house now-ish with possible positive cash flow.
The con is ultimately the total amount to be paid for the house

While a 15 year mortgage @4% APR would equal around $26,500 in interest. No positive cash flow, if anything I may have to pay out of pocket depending on tenants and rent. <$100-200 per month=(100x12)15=$18,000-(200x12)15=$36,000 >
The pro would be that I can get a house now-ish and could have the possibility of doing a home equity line earlier then the 30 year mortgage.
The con would have to be paying out of pocket with the mortgage.

If waited and paid all cash for a house I would guarantee a positive cash flow from renting out the other two rooms.
The pro would be the positive cash flow
The con would be having to live with my parents for another few years =(

There are pros and cons to each situation and I'm not even factoring other outside influences. Actually typing this out already has me leaning towards one way but I'm interested in the opinions of others about my situation?

Let me know if the way I format is confusing. I'm kind of new at this.

P.S. I know I use the word possible/possibility a lot but only to remind myself that nothing is guaranteed and life tends to throw a wrench to even the best laid out plans. ;D