Outreach to brokers will also pay good dividends. Brokers often have 'pocket listings' they've not published on any website. They've often not published their best leads, because if they do, and someone like you is using a buyer's broker, then they have to split their commission. So brokers will often initially shop their best deals to known buyers (who don't use buyer's brokers). Only if nobody bites do brokers then post deals on LoopNet.com, MobileHomeParkStore.com, etc. (and risk loosing half their commission, but at least they'll get the deal done).
You've got to convince brokers you:
1. have money
2. know what you are doing
3. and can close reasonably quickly
... but if you can do that, you'll start seeing deals that few others do. Tell brokers exactly what you are looking for - by geography, size, etc. The more specific you can be, the better. Then brokers will remember you the next time they have a deal that matches your criteria. You want to be knows as the 'Tallahassee seniors park guy,' or the 'Dallas Hispanic park guy' or whatever your focus is.
My 2 cents worth,