They're neither complicated or expensive but they do have some requirements that preclude it in this case.

I also intend to finance the majority of the properties I purchase and have heard that having properties in the name of an LLC or S-Corp could complicate matters.I want to be sure to protect my personal assets.  

If this sounds complicated, it really isn't.

I have found a buyer, but it is an individual that has pre-approval for bank financing which complicates the process a bit, in my mind at least.  

Any page on your website can be tracked as the page you're interested in (IDX listing) says www.yourwebsite.com/listing123 or /listing456 or /blog.If IDX goes to another site, tracking those analytics could get more complicated...If you want more in depth info like you want to know if Sally, who filled out a form on your site, is viewing your properties and what she's looking at-- this is the kind of information you'll have to hire a service to track.It sounds like you're wanting in depth info on how a specific lead is interacting with your site?

Folks that own distressed properties want a quick, simple transaction, and discussing any fees beyond their "walk away" money could complicate things and have you miss out on opportunity.

I figured, I'll start with something I can at least understand then go for a more complicated process.😊 pls feel free to share what you think of this approach if you like whether in agreement or not.

To complicate matters, if they are leaving, I want them gone now because in 2 months, the house will not be as desirable as it is now (Too many renters, not enough houses right now with school starting). 

The work arounds are somewhat complicated, and have possible troubling consequences should the marriage not work, should one party pass away before the lien is paid off, and would require changes in wills and intended inheritance.

@Andrew Yip Im late in the game but I use Fast windows or Contractor Windows for cheapy ones or if customer doesn't need quality, Irwindale windows for my Milgard needs, Jimmy is a really good guy, goes out of the way on my install, mine was very complicated and needed his expertise to explain to the architect what limited options they have.