I know J.N. Smythe who celebrated his 80something birthday recently. Still riding. I hope to be riding when I'm in my eighties as well- so it's possible that you have another 20 years. In that case, a Guzzi makes a lot of sense. The big drawback or question for the Le Mans models is the riding position. If you like it, then great. If it doesn't fit, then maybe one of the cruisers might fit better- they are also very good runners.
Vapor lock shows up on some bikes and not on others- I don't think there is a definitive fix yet for those afflicted. Mostly it depends on where you live- hot weather is bad, and short trips in hot weather is really bad.
Relays should be taken care of by '02 but you could order a set from Dan Prunske just to be safe.
His website is: http://www.dpguzzi.com/
Orangeokie makes a good point, though. If you don't want to deal with the hassles, then by a one later year model.