I went through post-bacc but still went to an allo school as did several other people in the class. You're supposed to rank TCOM first, but it isn't necessary. 1 or 2 people in the program even dropped out on Feb. 2 after they matched, but that's kind of shady.
As far as I could find, the clinical research & biotech degrees at TCOM are the shortest in Texas. Everything else is 2 years. As long as you don't screw around there's no reason you can't finish the program in less than 15 months. I went in to the program in August 2002 & defended my thesis in November 2003 (& I'm lazy) so you can get it done in a hurry if you're motivated.