I went with the "loud" Stainless Steel Specialities" pipes because they fit my limited budget. Seat-of-the-pants dyno says they improved performance. They look great and have not turned yellow.
Only drawback for me is they have a very slight downturn at the tips which can really pi??-off the '32 Ford
parked next to you at the car show when someone asks you to "fire-it-up" so they can hear your engine and you blow gravel all over the '32.
If I went with them I'd ask if they can make sure the tips are 100% perpendicular to the ground. Just my thoughts.
Whichever way you go, you'll be glad you did.
Best