Well, you obviously don't like what you've got very much or you wouldn't be wanting to do something different. If you want to try carbon, then get some GoldTip XT's and don't worry about trying to get down to 350 grains. You'll gain plenty of arrow speed. Even at 400 grains, you'd still be clocking along close to 290 fps, depending of course on how efficient your bow will be with lighter arrows.