Greg @ Worldwide, Sweetquads or The guys @ Rocket Factory.
Just like anyplace talk to a few places and get a feel for the customer service, get to know them and get your name known then you will be able to work with them on prices. Most places will be drop shipping items like the exhaust kits etc. They will all be paying close to the same price, so increase their purchasing power with a supplier and keep buying from the same shop. You will notice once your name and loyalty is established with a shop your prices get better than advertised. Don't be afraid to talk to them and let them know what price (to your door) you have found it for elsewhere, they will say a variation of one of three things, that's a great price but and I can't do it for that, Well,....If I match it are you ready to order, or I can beat that.
Remember it is better to make a $5 than loose a potential customer to a competitor!
BTW, I got mine for under $650 to my door using this approach.