if you can get a decent discount rate at your local Kawie dealer, you can replace everything in the motor, minus the engine cases, for about $6000...then you'll have the reliability, providing you're good with the general maintenance...this was the path I chose because I plan on keeping mine for many a year to come.
I kind of went the same route since I want to keep mine for some time. I sent my engine off to Tom Morgan for a full rebuild, but had to since I grenaded the piston and it took out the bottom end and really screwed up the cylinder also. I needed the full Monty.
I had him do his cylinder, head and power valve mods also, but without those, it would have been about $2600. But, that was including cases, which added about $500 to the bill. That was for the top end, cylinder welding and replating, bottom end, gears that needed replacing and the clutch.
I'd definitely replace that top end at the least, as if it is old and crusty, you may end up needing a full rebuild whether you want/need it or not.