But I hit a wall.First: Trying to find out what similar properties in the area (10 m radius) rent for, I used rentcast and rentometer for this, but they gave me two very different results.

While trying to understand your thoughts on this, why did you think out of state investors would not consider it?

What are your tips on finding and evaluating areas to purchase?

Quote from @Sarah Kensinger: Reach out to @Jeff Chisum and see what options you may have for this property. 

Did you receive security deposits with interest and pro rata rent for the month at settlement?

Then use the extra roommate rent income to pay down your mortgage and look to refi to a lower payment in the future (3-5 years) - so it cashflow when you move out.You could also choose the smaller unit and STR the other unit to generate more cash to pay down your mortgage and refi, so it cashflows when you move out.Bottom line: you'll have to get creative to solve your cashflow challenge!

Good morning Simon: what is the best phone number for me to contact you?

I'd be happy to connect.  

Looking to see how I can tell if a vacant lot/land is allowed for a single family home (SFH) or duplex to be built on it.The area is West Palm Beach, Boca Raton, Ft.

Meetup is a good place to look for these.