high mounts dont improve performance any, only look/sound. they've got the wrong routing for performance gains.. and this is why you cant get a 'full system' high mount.
i had the Micron carbon standard mount on my '05. it was cool but you're not going to help or hurt yourself any buy getting carbon as opposed to ti.. the weight savings, if any, are unnoticeable. i wouldnt bother with the Micron high mount for one reason, its the exact same fitment as the standard mount, the only difference between the Micron standard, and Micron high is the angle of the can once fitted. the standard mount may make a little power.. the high mount wont.. and the standard mount can accept the headers, making it a full exhaust, if you choose to do so sometime down the road.. the headers will not work with the high mount. the standard is pretty high on the 04-05's anyhow.