Go with 1.5" from a reputable supplier. Rough Country has sets of 4 for $118 shipped to your door. Have had mine for about 30k miles.

 

Interesting... I checked out both the Spidertrax and AlloyUSA websites and I guess it comes down to color. They both seem to use the same Aluminum type and offer a centric design. I'm using the AlloyUSA variety as that was what I given when I asked for spacers. At the time it seemed like I didn't have a choice. I guess I did after all. I like the red though.

 

anything machined alum hub-centric is good to go. I use RC's hub-centric 1.5" spacers. On for over 20k no issues of any kind.