If you must use a mechanic/dealer, use the slip on brand that they will sell you so that they can get all the parts they need for assembly and you don't have to deal with that... (you will likely find that they only sell the Jardine, but I've seen a new Supertrapp as well).
IF you are paying a mechanic in a local garage you can buy whatever slip on you want that will fit, even if it needs modification
encouragement to fit, like a HD conversion (mentioned earlier) or an off brand product like MAC or something you can get at JCWhitney.
You will pay more than the prices I will list at a dealer, but if you have to buy your own to take to a local mechanic or try to do yourself, you should look for deals like these (I'm not recommending this online retailer per-se, just using them for an example, I often use e-bay or
Ron Ayersor
Bike Banditetc., myself)
Supertrapp link $219.56
Jardine link $169.96
MAC Exhaust link $92.61 (this one is listed for older savages but it will fit all savages and the S40 too)
JCWhitney Exhaust Options
link (all of these will require extensive mechanicial knowhow to install since they are NOT specifically made for the Savage mounting brackets)
I use a Jardine myself, I like it, but it did turn blue and is impossible to keep really shiny if you want showroom chrome... But I like it for everyday driving and a performance boost with deeper sound/rumble (also, I’ve had some trouble keeping it’s connection to the header well sealed as well, the disk provided with the Jardine melted to nothing and I had to experiment to find something else that would fully seal that connection [short of welding it]) .
Additionally and VERY IMPORTANT: whichever exhaust you choose, putting it on yourself or having a mechanic or dealer do it, you MUST rejet your carb at the same time (a bigger main jet at the very least) and retune the air mixture screw because the new exhaust will change the back pressure from the stock configuration and your bike will not run well if you don't do the re-jet at the same time you put on your new savage exhaust.
Good Luck, Have Fun, and Welcome to SuzukiSavage!