I, like a lot of people, bought stuff from Zanotti's before they closed - good prices and great service. After they closed, there were a lot of threads here of people looking for a good place to buy parts.
Search for threads in the last year with "Zanotti" in the title. You'll find a lot of recommendations.
I understand New Castle Harley in New Castle, PA took over the Zanotti's online parts business. I've also heard good things about ...
Horny Toad in Temple, TX
Lake Shore in Libertyville, IL
Surdyke in St Louis, MO
You can find parts numbers here: http://partsfinder.onlinemicrofiche.....asp?make=hdmc
Shop around as which dealer has the best price seems to depend on the part you are looking for.