I got a zx900r seat to fit up to the tank. I ended up cutting it and the C10 seatpan up and grafting them together. the zr seat was not flat like the C10, so did not look right back toward the rear cowl. fits up nicely to the tank now.
I also got some 43mm clipons and installed them. (43mm because those are ZRX1100 forks, not stock C10). I like the look better. I also have some clubman bars on order. I will try them as well and decide which I like better.
lastly, I got a C10 left footpeg and mounted it to the C10 bracket. it effectively gave me a 1up-1back rearset. Hopefully the ergos will be better.