After my first 20 min./ 20 mi. ride, I knew my C with stock seat and handlebar wasn't going to be comfortable riding. Arms ached from shoulders down. After seeing 2 styles, the round stock Phat risers, and the flat or more square stock Rivco risers, I decided on the Rivco's. This was 7 years ago, so I don't know if they like many mfg.'s are still in business or not. I do know that the early C's you can order up to a 6" riser w/o changing cables or hoses. IDK if anything on later years like yours would be different or not. Good luck. BTW I'm 5'10", 33-34" sleeve.
2003 1800C Black w/ H-K 3", PC III, Clearview w/s, Hondaline backrest, XM sat. radio, MB 12" shocks, Prog. fr. spgs., Wolo, SPyKER mod, Glen's gas cap, Paladins, Drag Specialties Popsicle pegs, K-N, blackened engine, Kury RTB, mirrors & r. boards, blue LED's, Rivco tach & risers, LeatherLyke bags, backrest bag, w/s tri-pouch, Gen. Altimax RT43, Mich. Cmdr. II, Ult. Lowrider, Showchrome grips. 12-18 VTXCafe Bike of the Month