@Jeremy K.
Congratulations... you've done well for yourself.
There are several options you are not considering. I will advise you on just one option that you haven't considered:
Remember in Monopoly what happens when you have 4 green houses? Well Jeremy, you have 8 green houses! It's time to trade up.
If you have 8 houses with 8 LLC's, (which is the right way to own them for asset & liability protection) you've got a lot of overhead. Plus, you have to know landlord/tenant laws in 2 states (i.e. 2 different leases). You have to manage 4 different PMs! Do you see where this goes if you continue on your current path?
If I have 1 apartment complex with 8 units, I have the same income as you do, but my expenses are lower. Plus, I have only 1 LLC and 1 PM to manage. I also have only 1 roof, 4 walls, 1 mortgage, 1 lease template, 1 insurance policy, 1 electric bill, 1 tax payment, 1 set of laws to know, same vendors for HVAC, plumbing, etc.