network, meet people, go to meetups, take people out for coffee, and walk as many properties as you can. 

For the son to qualify for the $250k exclusion, I believe he would most likely need to meet the ownership and use test, meaning he needs to own and live in the home as his primary residence for at least two of the last five years before the sale.

Mission KS is a hot area in the metro, not surprised it sold fast

You can meet local investors by registering to attend real estate events in your area: https://www.biggerpockets.com/forums/521-events-and-happenings6.

They make bank, but the software they provide is like deal machine meets the MLS and I do kind of want to try it out.

Certainly partnering with companies that have consistent replacement properties available makes sense if the properties meet your investment guidelines.  

Right where interstate 79 and 376 meet so great location.

If you don't meet that 12 month seasoning requirement and/or want to hold the property under an LLC, a debt service loan may be a better option.

Have you considered dropping by one of your local REIA meetings to see what lenders your peers are using?

They have regular meet ups.