Gargraves (and Ross) are made in the good ol' U.S. of A.. Never experienced a track availability in all my years. Some of the ancillary products/accessories they sell from other manufacturers may have occasional availability issues.
If you will be running the track outdoors, I'd suggest sticking with their plastic ties, stainless steel rail for weather resistance.
Gargraves are great 'down home' folks. If you have ANY questions about what's best for your situation, give 'em a call.
Better yet, if you're attending the York Meet in April, they'll be in the Orange Hall....as will Ross (totally compatible with GG.)
FWIW, always....
KD