Webasto also has a bolt in kit for the 3rd gens too. We sell webasto, so thats what I put on my truck. There both junk when they dont work, great when they do. Yes I have worked on them all. The best info I can give you, a great dealer with support is what I would look for. Espar/Webasto have pretty much 50/50 market share of the world. The heaters come with pretty good instructions, so if you have abit of wrenching skill, you could put them in. The espar has a cool fuel pick, but I think there mounting spot is . Websato mounts very close to the engine, but there fuel pick up is different. Not sure about espar warranty, webasto has 2 years.