Some thoughts -
- Not sure if you are just using Craigslist but also look at places like hotpads.com, padmapper.com, zillow.com or trulia.com as they may have some places listed that aren't on CL
- Seems odd to me that someone would be taking your application and then not following up. Are you seeing places in person and filling out application or is this all sight unseen? I always meet tenant at property and if they fill out application I then proceed through approval process. Maybe you need to find someone who self manages their property vs. a property management firm
- You might want to get a relationship with a local realtor. While most don't have any incentive to find you a rental they still might help. For example, my RE/MAX office runs an internal newsletter every day that goes out to all local 300 agents and has a spot where we can say we have someone looking for a rental property. Many realtors have their own rental properties so you might get in front of a realtor looking for a tenant. If you tell realtor you might be buying in future they may be more apt to help this way.
Good luck