Creating a database of multifamily, self storage, and mobile home parks.

I've been creating a database of multifamily, self storage and mobile home parks using county gis sytems lately. However this is a tedious process, and I was wondering if anyone had a better way of going about this and building a database of properties that fit a certain criteria. My criteria really is the infant stages of being developed but anything that sold pre 2008 is something that I've been targeting. Are there any particular websites, databases, and market research platforms that would allow me to go from city to city collecting these properties. I'm primarily focused on Georgia currently, but plan on building out into surrounding Southeast cities. I'd appreciate all the help I could get on this topic.