RWW,
I'm not familiar with the Kubota model, but I do have 2 JD grasscatchers - the 10cuft 3-bag 'Manual' model and the 13cuft hydraulic Dump Bagger for a JD4100.
I use them to pick up grass from mowing, and to pick up leaves in the fall. Got LOTS of trees around here, and the leave fall is REALLY heavy. Using stove pipe from the local hardware store, I fabricated a vacumn 'head'. It works pretty well - will even pick up wet leaves in a pile.
Both Units ride on the 3pt, and are powered by a little Honda 5.5HP vacumn engine. The Vacumn engine works great, really picks up the leaves and grass. I'd have preferred that the vacumn be PTO powered, but that would have increased the cost significantly. (The little Honda engines can be had pretty inexpensively in OEM quantities.) Ahh, next project ...
The Hydraulic Dumper beats the manual one hands down, of course. The manual one functioned well, but having to get off the tractor and wrestle the 3 bags off and dump them is a lot of work. The Hyd Unit connects to the FEL control valve, and so dumping is controlled by the joystick. Specifically, the process is (1) back up to where you want to dump, (2) lower the 3pt to set the unit on the ground, (3) Dump the hopper using the joystick.
I bring this up because the unit would probably work with your tractor. AND the color won't even clash! /forums/images/graemlins/cool.gif The hydraulic dumper is black.
The area you'd have to research is getting a mower boot that connects to the vacumn hose. I believe the hose is a 7" Diameter.
Let me know if I can give you any other info.
Caretaker