Bouncing Tracks with Silence

Hello all! 

I'm running into a bit of a logistical issue. I've been making trance in Sonar for years and am starting to work on a performance workflow in Ableton. To do this, I'm trying to bounce each track in my projects to individual .wav files. 

I realize that I can do this relatively easily from within SPE8 (haven't gotten around to upgrading) in the Export... menu, but when I do, the clips are different lengths (as expected) since they start at different times and end at different times.

What'd I'd like to do is bounce the individual tracks so that they are ALL the same length when I'm done; that length would be the total length of the project.

I've gone through a few projects and added a quarter note to a measure before and after the start of the song to each track, then trimmed later, but this is a massive pain when I'm working with 25+ track projects. 

Any thoughts? 
-Vince