I think those three would take off around 250g, without compromising performance?
Bars maybe, saddle might work but there's no guarantee that the carbon one will suit his arse as well as the standard Arione, and SRAM Red cassette doesn't shift as well as Shimano, and is not available in 12-27. Could always go compact with an 11-25 and reduce both chainrings to keep his top and bottom gears the same, but that could get expensive as the carbon cranks don't have the swappable spider.
Bars maybe, saddle might work but there's no guarantee that the carbon one will suit his arse as well as the standard Arione, and SRAM Red cassette doesn't shift as well as Shimano, and is not available in 12-27. Could always go compact with an 11-25 and reduce both chainrings to keep his top and bottom gears the same, but that could get expensive as the carbon cranks don't have the swappable spider.