Check out my
thread in the tracks forum. I posted unfinished pics of my unfinshed track, and something of an explanation of how I did it. Also be sure to check out Legion's track. He posted a link in that thread.
Both tracks are portable because the fold up.
I think 1x3 is overkill for your track. 3" is really, really thick, and it will just add extra weight (in consideration of portability). I ripped a 2x4 down to 1x1 for my frame, and though it's not bullet-proof, it's sturdy enough that I wouldn't be afraid to mail it.