I've just purchased a new road bike equipped with Shimano 105 components (compact double), but I had the chance to test ride a friends bike with Sram Rival and I LOVED the small hoods. I also liked how it shifted (double click was very intuitive for me).

If my goal is simply to get the smaller brifters on the sram, what other components do I also NEED to replace? I'm wishing to compare costs between upgrading the entire component set or just the bare minimum parts to get those smaller brifters.