The custom enclosure that my Sav came with, had plastic channeling which promptly broke. I wound up buying about $80 worth of aluminum channeling & angle from a hardware store. I attached both pieces of channel to the angle, & countersunk screws to hold the assembly to the enclosure. Just for good measure, I used liquid nails also to hold it in place & caulked the seams with silicone caulk.
Really any kind of channeling you can get ahold of will work fine, just make sure that it will hold up to the abuse of a sheet of glass sliding over it every day, as well as any other variables like humidity & water.