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.
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.