I played Travian for a while, got pretty obsessed, really didn't like some of the aspects of the combat system and wide-spread griefing, so I set out to create my own game similar to Travian. I got a lot built and felt pretty good about the direction it was headed but then the weight of it bogged me down and it will probably never get finished.
I tell you all of this to also tell you there is a lot of work ahead of you, more than you realize, and if you are going to get any kind of professional coding done, you're going to have to pay real money. If you rely on volunteer work, you will have a hard time getting any one coder to stick with it for very long (likely your volunteers will be very young or in college and therefore pretty transient) so you'll end up with blocks of code no one understands, so the next volunteers will probably want to scrap what was done before (easier than trying to figure it out).
Anyway good luck to you, I had tons of fun on my project as I learned a lot about AJAX and jQuery which I have been able to apply to my current work.