john lucas
Go with the U it's easier to sharpen. With all tools you can still screw up the edge when sharpening if you grind too long in one spot. The V gouge has a steep transition between the sides and bottom of the V shape. It's very very easy to get a dip in the cutting edge at this point and takes very careful grinding to avoid this. The U shape doesn't have this same problem.
I have a video on youtube that shows how to correct sharpening problems. When you get to that point just ask and I'll post it.