To agree with some of the previous posts, it sounds like you CAN bi-amp your center. You, however, don't need to. Typically, I'm bi-amping mine. But, I'm a mad man.
If you do have to run a wire, fish tape works great. BUT, even easier if there is already a wire there and it is a semi straight shot in the wall. Just tape (hook, attach, etc etc) the new wire(s) onto the old wire pull gently and have someone feed as well. Oh, and keep your fingers crossed.