From Wiggle/Merlin/CRC. You might want to look up this off-brand that sells less expensive shifters than by this little known company called Campagnolo that will sell you shifters new for about 100 US dollarinos
Since you're looking at RX100, I'm assuming you want 8 speed. The Campagnolo 10 speed shifters will work with Shimano 8 speed everything else, you just won't use 2 clicks.
Since you're looking at RX100, I'm assuming you want 8 speed. The Campagnolo 10 speed shifters will work with Shimano 8 speed everything else, you just won't use 2 clicks.