OEM and After Market Parts Dealers
Cruiser Customizing - Sells all type of parts for metrics a little pricey but a good reference for parts

Pipe City - Good priced pipes

HellRiserCustoms - They have good pricing on Baron's stuff and pretty good prices on pipes

Motorcycle Enhancements - They have a forward control relocation system that moves your forward controls 4"s

Cruiser Customizing OEM Parts - Not sure how long they are going to support this site but its a good reference to stock parts and mechanical pictures. If you add a part to the cart it will give you a part #. That part # is the Yamaha part # which you can cross reference with any other site like cycle-parts.com.

Cycle-parts.com - If you have the OEM part # they will give you a good discount. Please reference the the link above to get the part numbers.

Trailers
Baxley Companies - Saw these guys at Laguna Seca last year. They also have some nice stands for sport bikes.

Razor Trailers - I have not seen these in person but since I ran into the site I thought I would share!