Re:
The green one was up for sale recently and is back up. I love mine.
The unit is also real nice. I have had a punt on it!
Imagine the karate monkey is more a general workhorse but the kona is quite big. Sizing it up its not that large for an XL I didnt think.
Much the same really then I would say. Are you going geared? If so kona might be easier unless you have some monkey nuts for the surly.
Both are going to be fairly heavy.
I'd think about what this bike is going to be used for against what you have and choose on that basis. KM is a good versatile bike could see it being used for touring and whatnot but that might step on your toes for the custom you had built?