Look at Arcticcatpartsnation.com
The have exploded views of different sub-assemblies so you can see what you have and what you need.
They have awhole new carb for just a few bucks more than whoever quoted you to rebuild yours.
'03 400 Manual
Exhaust Baffles Opened Up
Slide Drilled & Clipped
2,500 lb Champion winch
2 55Watt Replacement Lights
4 27X10 Pirelli Mudweisers on Factory Wheels