I think I need a Mortgage Note Purchase and Sales Agreement and a Mortgage Assignment Agreement along with my simple assignment contract which I already have...

I enter them manually, in excel first then it is as simple as copy and paste.

If it were only so simple.

Plain and simple.

You would be surprised how long something as simple as providing general applicant information will take...Something that I did not do with my first rental property (great lesson learned) is to ask for concrete evidence, e.g., receipts, of the current tenant's previous 3 to 6 months rental payments.  

In simple terms, your gains get transferred to the new property and continue to grow tax free until you sell the new property.

Simple preference aside, renting is easier and scales more easily than flipping.  

The answer for me is pretty simple...

I am agree with @Katharine, simple first then upgrade when you need it.

Most prefer to avoid this cumbersome process as can be lengthy and expose a simple sale between parties to overbidding by 3rd parties who get wind of the court sale.