Had a local fab shop build me one. It's over built, but it'll hold anything I care to get to the truck whole. IMO, there are 3 things to look for, will it fit your truck bed and does it swivel and can you let the tailgate down? Mine does all three.
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We are gonna try to design an all aluminum one that has no piece longer than 2' and fits in a duffle. The one pictured worked great, but it took up quite a bit of room in the bed. For long trips that was a problem as we needed the space.