I'm thinking that detail caprate/COCR calculations can be done after the basic filtering. 

Honestly, in my experience filtering your investments via an LLC is the way to go.

It scrapes the internet, and you can easily filter by your location. 

Go to craigslist, filter by Real Estate for sale by owner and call the first page (if they have a phone number).

My system uses one of those big filters that are only replaced every 3-6 months (not your standard 1" filters), and they cost like $30 a pop.

Fill the void, to the 1:1 slope with stone(1/2"-2" size), filter fabric, then a 2' layer or so of 6"-18" rocks.  

Sites like BiggerPockets provide a plethora of information on real estate investing and (best of all) people (real, live, breathing, typing, etc.) with whom you can interact regarding real estate investing.

I with I could filter them, but still seems like it could be useful.  

@Jay Luke  @Michael Your success isn't just limited to buying a list of course, and the response rate will depend on a number of aspects:For exampleYour list and the quality of the list (Absentee Owners, Probate leads, Divorcees) and what filters you use to define your list.What you write in each letter sent out.How often you follow up with the same prospects.Do a search for "ListSource" to find out what other forum members think about using this as a method of finding deals.

I would say It depends on you and what work you will be doing yourself.showing to potential tenantsdrive by inspections inside inspections (I change furnace filters, and inspect under sinks)regular maintenance / upkeepTurn overs / cleaning paintingI am not a big operation and never will be, so I do most things myself.