I am fairly new to armor and would like to build some US artillery pieces. I would like to hear some thoughts about AFV Club kits and, in particular, their 8" howitzer and 155mm gun kits.

AFV Club's artillery pieces are great. Nothing bad to say about any of them. They are highly recommended.

Ditto to what Gino says about the kits. The only thing you might want to consider if you want to do a WW2 vintage 8" howtizer or 155mm Long Tom are replacing the resinwheels and tires with a set from Masters Productions of France. The kit supplied ones are the ones most common post WW2. The resin set correctly backdates the arty pieces and also includes the M1 limber, which was used when they were towed by an M4 HST.