you want to put a carbon road fork on a dirt jump bike? that's not going to work.
1. you need a fork designed for 26" wheels that will accomodate the type of brakes you're going to use.
2. If you want to go rigid, you'll need a fork that is "suspension corrected". otherwise you're going to end up dropping the front end of the bike waaaay down and messing up the handling. something like the surly instigator fork....
http://www.surlybikes.com/forks.html