The questions you ask are good ones, but they cover too much territory to answer in an online post.PS.

We have two lots of land in south Saint Paul Minnesota which total approximately 2 acres right next to each other.

I have about 1.5m in total equity  

I have been reading a little bit on data mining by going to places like NETR online but not exactly sure if that is the right way or how to start. 

you could sell 4 rental for total aggregated of 600k for example.

There's a ton of information online, including here on BP, that you can research.

Bottom line is this: with Texas LLC (Texas Sec of State provides an on line FILL IN the blanks form ) it cost $350 to form the series LLC, there are NO annual fees, and only one “information report” (single 1/2 page verifying agent, manager and address) to file every year.  

If you are paying cash for keys a very important stipulation is that they do not receive the cash until you receive the keys and they are totally moved out. 

I would say my main concern with Invelo is that I believe once I upgrade to the paid plan that I can only add tags to the total prospect where in ReiSift I have the abiltiy to tag prospect phone #'s (wrong # tags) and other individual stats per record. 

But, an LLC will not limit you from liability in total.