You cannot get any meaningful answers until you specify what is your "side gig", how much money it's going to bring and how much expenses it's going to incur, and what kind of expenses.And, as a rule of thumb, unless you clear $50k after all expenses, you probably will not benefit from any entities tax-wise. 

It's a business - acquiring/building, managing, and growing a business. 

Knowing your long-term plans can help you build a long-term financing strategy so that you are not just worried about purchase number 4, but also purchases 5 - 20+ (if you plan to continue to invest).I'm an investor and licensed mortgage broker.

Specifically from the Caged AC Unit into the attic (concrete slab so no crawl space).I was thinking of just building a tall vertical box to place this into.  

Go to BUILD YOUR TEAM at the top of the screen and look for local investors or meetups in your area.

If I were to guess, I would think that the new administration will bring positive change to the housing sector by removing regulations that impede builders, and affect building material costs. 

these investors were all chasing easy OOS cash flow:https://www.biggerpockets.com/forums/963/topics/1195280-expe...https://www.biggerpockets.com/forums/48/topics/1160450-run-i...https://www.biggerpockets.com/forums/48/topics/1137397-balti...https://www.biggerpockets.com/forums/52/topics/1010977-12-00...if you're serious on investing in an OOS market i'd pick one, get to know it, go to it in person, and build a team, and then determine what would you need to do to get a good return in that market. 

Go to BUILD YOUR TEAM at the top of the screen and look for local investors or meetups in your area.

You can build a deck around them as well - or not. 

I informed the seller that because of the overlay, the property may be 2 build eligible in-spite its small lot size.