Bump
On a side note, this should be pretty easy shoes to fill, fellas. Smarty, Ajax, PHP? They all go in hand and hand. I've integrated all of them together without issues, and if you don't know smarty, it's pretty simple to pickup.
Ajax, well, there are libraries for that - I personally use both JQuery and Prototype, and anyone serious about Ajax has used them in one application or another.
Maybe you aren't addressing your specific needs to them clear enough. Some guys will take their time because they don't know about existing frameworks or libraries that can make the job much easier and faster. And when you push it on them later, and they don't know it, there's the learning curve. I reccomend looking for Developers that know specific things like JQuery or Prototype, some sort of mvc framework, or a framework period, and have knowledge of smarty and anything else you desire.
Just some advice ;) Good luck in your search!