Steer clear of the X2N for what you're looking for - that's a super-high gain pickup, so if you want clarity, it's probably best to gow with something with quite a lot less gain, especially if you'll be balancing with those singlecoils.
(sweet guitar, by the way!
Um... Hmm. Listened to the clip, and I recognized the tune in the middle (blanking on the name, the "So she told me she's got a gun..." song. Who the hell is that, anyway, I liked that single), but couldn't place the rest of 'em - is that the same band, or is that a few different ones?
Anyway, it sounds like you're looking for a fairly bright medium-to-high gain humbucker. The Steve's Special might be a pretty good match, but I've never heard it in ash before. It's a slightly scooped pickup, but to my ears (going from a Blaze II, which is the pickup the SS is based on - I guess the story goes Petrucci liked the Blaze bridge so much he asked dimarzio to build him a 6-string version, can anyone confirm this?) it's the lower mids they scoop, and there's still some decent upper midrange. Then again, through a Nomad mids are never a problem anyway... But I could see the Steve's Special working fairly well with ash - it'd give you the brighter tone you're looking for, and good upper-midrange definition while still having full bass.
Worth a shot, at least.