I'm running Eibach 2" drop springs. There's no problem with load capacity or towing - they work just fine with the Autoride shocks. If you can get past the annoying flash intro page,
www.eibach.com is a great site, and they link to a number of resellers.
Belltech and GroundForce are two other brands.
You will notice that the ride quality is degraded a bit. However, handling improves at the same time...
Take care,
Jerry