Thanks everybody for the feedback. I've since done some more looking around. I drove an hour to a different Tractor Supply, and they had a King Kutter brochure showing the 48", but they couldn't find a price on it. I then went out to their web site and looked in the "Blue Book", and it only lists the 60 & 72 inch ones. So maybe some stores can special order them, others can't or won't? That might also explain the inflated price over the larger ones (special order, no quantity buying?). In any event, the owner's manual says 375lbs. for a tiller. Even if this is a conservative number, I think the 600lbs of the KK make it a poor candidate.
I looked into the Sovema, and spec-wise it looked pretty good. Unfortunately, they are a bit pricy, and harder to find a dealer to ship one reasonably. The Land Pride looks really good, but very pricy.
I found a dealer that can ship me a Caroni 48", model FL1200ASC, including shipping and tax, for $970.00. The specs say it weighs 408lbs and requires 15-40HP. At this point, this looks like a winner. Does anybody have any experience with this or other Caroni tillers, or other equipment they make?
Kevin