Scarffings not that bad - we just use a combination of a hand plane and belt/disk sander, and the job is pretty good. You don't need to aim for perfection - the epoxy is going to cope with gaps pretty well. Other builders reckon that a butt joint is ok, but I disagree, and I wouldn't use one on a mozzie, but finger joints aren't too hard to set up (with the right jig) and seem to be getting popular (although that may be down to the prevalance of CNC produce kits).
However, I spotted this scarfing jig the other day:
http://oneoceankayaks.com/stitchglue/plyshophtm/scarfjig2.htmand was thinking of giving it a shot on the weekend.
