John, here's a link to Jerry Work's
Getting the most from Festool sanders, it's a nice overview of the sanders. This might be a good place to start.
The ETS series are random orbit sanders offered in two sizes, 125 mm (5") and 150 mm (6") and the 150 mm models you have the choice of a 3 mm or 5 mm stroke. The ETS150s are wonderful sanders but might be too big for your refinishing project unless your cabinets are flat panel design. The ETS125 could be a better choice given its smaller size.
I'd advise you to take a look at the small orbital sanders, RTS400 and DTS400. The DTS is a iron shaped and the RTS is Festool's idea of a 1/4 sheet sander, it's pad is rectangle, 80X133 mm (about 3 1/4" X 5 1/4"). One of these could work pretty well.
Of course we don't know the extent of your refinishing job, its likely to be a more than sander job in the ideal situation. One of the great things about Festool sanders are the available accessories pads and Festool abrasives. For example, Brilliant is made for sanding finishes and the interface pad is a soft pad that helps sand slight curves and profiles, this could be useful for sanding raised panels.