Eibach quit but there is at least one manufacturer still making lowering wagon springs. The springs didn't interest me because they did a 2" drop which was more than I wanted to go. I posted it on here but I cannot remember the manufacturer anymore. If you search this forum and the Wagons forum, you should come up with it.
I put a set of Eibachs for an SS in my wagon, and they didn't drop it very much at all. Maybe an inch to inch and a half tops. they aren't the cheapest, but they should achieve the results you're looking for I would think.