Great car, chaulk another GT/CS up for Texas. Are two different plates legal in Arizona?
Robb, you can get original black 1968 Texas plates that really look cool for $75 from Johns Mustang here in Houston. I found mine on Ebay for about $40. I think it's a nice touch. Just remember you need a pair in good condition if you find them on ebay.
http://johnsmustang.com/Catalog/273/
Congrats on the new purchase