I dont want to pay people to 'pick things up on the job'. I want people with a proven track record in the language we use.
Google would disagree. As would Microsoft (they were very interested in interviewing me, even though I've never done Windows or C# programming and made that clear on my resume), Facebook, Amazon (http://groups.google.com/group/mi.jobs/msg/d81b6c1fa8f361fc) and other serious software successes.
Sounds like you want coders, not developers. What reason would talented developers (the ones with offers from all of the above, plus start-ups competing with you) to join you?