I would think you could buy extruded aluminum online at needed lenght. Something like this:
https://www.zoro.com/8020-t-slotted-extrusion-10s-72-lx1-in-h-1010-72/i/G2108382/?msclkid=9e003258f048167023db56a82f12d7bc&utm_source=bing&utm_medium=cpc&utm_campaign=pla_rlsa_na_na_na_Product Viewers -...
About as far setx as I would go would be around the Houston/Katy area. I would say on shipping it is going to be expensive but will try and get you a price.