I could have put three B class doubles in front of you with good numbers before you finished reading this... time is money!

They essentially act as a property management company but charge double the fees for fewer services.

I want to replace it with a small 2 bedroom 800 sq ft house.

These are the pros and cons of these markets as I see it: Riverside: Larger units with more bedrooms; I can afford better neighborhood with less crime (50 percentile); properties are less old but ugly. 

A good starting point would be a 10% 2nd home loan or an owner occupied 5% loan where you can convert a basement or studio into a simple 1 bedroom unit and basically let your guests pay your mortgage. 

Also, how many bedrooms are in each unit?

If it says on the website they pay $1,500 for X number of bedrooms, they probably pay closer to $1,150 once they account for the utilities.

Rick, I am preparing to convert a detached garage in Anaheim into 2 bedroom ADU.  

However, if you have a more extensive portfolio or plan to become larger in the next year or two, I would look for a double-entry system that allows bank reconciliations.

Since you plan to theme it and didn't put a number to that, lets just say $75,000 conservatively, including garage, bedrooms etc.