Buy what ever you want that visually appeals to you. You can always change the sound / tone by modifying the exhaust. Most GL1800 aftermarket exhaust systems have 2.25” or 2.5” internal pipe inside the muffler canister. A baffle insert can easily be installed inside to quiet down the tone.

I have a set of TBR exhaust. It’s internal spiral louvered pipe is 2.25” and runs the whole length of the canister body. The end cap can be removed and either packing of stainless steel or fiberglass can be added to muffle the sound. Or you can do what I did. I cut the oem spiral louvered pipe off the end cap and installed a T304 stainless steel 2.25” pipe instead. This pipe has no holes nor louvers. This way it is actually straight pipe while the muffler canister body is just for looks. I did this to reduce the sound at cruise rpms of 2200 to 3000. It is quieter at cruise the stock TBR but louder under full throttle.