wisteria

I have been afraid to try--knowing it might take years til I see a bloom.
Now a nursery man suggests that either Amythyst Falls or Blue Moon will likely bloom in the first or second season.

What experience do you have concerning these 2?

Skip ALL the sinensis varieties, and make sure you are using the "Floribunda" or Japanese varieties. They bloom much younger, and are usually blooming age when you buy them. For the years they take to bloom, and the length of time they stay in bloom, it really needs to be a show stopping varietie, like W.floribunda "macrobotrys" Frank

Amethyst Falls is a cultivar of W. frutescens and Blue Moon is W. macrobotrys so they should both be fine.