If they are the previous owners, it can be a little more difficult. 

Question- 1) I thought there was somewhere in the calculator that you could then see what you would need to buy it for in order to hit the going cap rate or the cap rate you are looking for? 

So you'll need  calculations for NOI, and cap %. 

Many NYC condo's will not allow subletting so lease options can be difficult and again those price points are WAY above $400K!!

Is this difficult?

I would think your a slam dunk at a bank.. but Visio is for real.and your smart to know that there are all sorts of fake lenders on the internet.good place to start is to see if they are licensed and then look up their license.. also dont let the tax dog wag your tail.. sometimes its best just to take your cash pay cap gains at these historic low rates then to buy something that is not going to do much for you.and if you don't get the benefit of no state income tax in Texas i would be cautious with that state prop tax's and other weather issues. 

I would talk with commercial lenders first, but it will be difficult without a track record 

Is there a rental cap already in place and are they trying to decrease it? 

It can also be difficult if not impossible to access if needed in the future and can vanish with a market correction.

There are plenty of books on commercial real estate/CAP rates.