I purchased kit 5462446K body mount kit for use with a fiberglass tub. This kit would be compatible with a metal tub as well as was designed for an OEM tub. All mounts are of rubber and metal construction, the stamped sleeves being of good quality. The rubber isolators are also well made and are softer composition than polyurethane. This translates into a softer ride than with poly mounts, and is neccessary when using a glass body because they won't tend to punch through the glass mount pads with time, they provide more cushion.
The only fault with them is that the rail mounts are not the same diameter as the OEM mounts, these being about 75% the size. For the person who uses the jeep offroad exclusively, this could be a problem down the road as life of the mounts may be shorter. For those who operate on road as much as off, they can expect the mounts to last the same as OEM. Plus the ride quality is much better with the rubber composition as compared to polyurethane.
I used washers between the body and rubber top mount, which aren't included and are not absolutely neccessary but I used these with 1" body lift blocks. When using without lift blocks I wouldn't use washers because it's too easy to overcompress the mounts, causing the inner leg of the sleeve to contact the washer and negate any vibration dampening.