A third model (which falls under the second) is a tiered services like someone else mentioned in this post.

I'm very much in the learning stages but have decent financial modeling skills and a MBA which should help me get started.

I just look at every area I go to and evaluate if it works in my model.

I applaud your business model and it's success, keep doing what you do.

Turnkey is really a model that plays well where cash on cash return is good.

We bought for $1,000, out $8,000 into it and that year and model sells for $19,000.  

My main concern about this business model (even though I have a few!)

I'm a hands-on blue collar type landlord thinking about changing my business model to scale up my number of rentals.

You should never tie an option to a lease, or a lease to an option.If this is your residence,Offer a lease purchase (screen buyers)Separate lease, 12 mo term, market rent.Separate sale and purchase agreement, 3% earnest money, non refundable, with long term closing date, say 12 months.Send LP tenant buyer to mortgage banker IMMEDIATELY.Send LP tenant buyer to get assistance improving credit and FICO scores. 

To avoid double taxation you need to setup a recognized entity structure such as a LP.