You gotta be kiddin me. I can't find one anywhere. I looked in this week's Want Ad but found nothing.
I wouldn't think there are too many people looking for ones capable of 4'.
When I was in high school I used to work for my uncle who did logging and a small cordwood business, about 100 cord a year. We used to cut it to 4', split it, and stack it. Then we'd cut it to 12", 16", or 24" when it was dry for the customer on a sawrig and throw it in the truck for delivery. It was a pretty efficient operartion actually. Unfortunately, after he passed away, the skidder and splitter was sold. JD skidder and nice, rugged homemade splitter too. I wish I had them back right now!!
Anyway, I would like a 4' splitter for my own use and to sell a little exta wood for some extra cash.