Just curious, why so unhappy with the rim brakes? Or at least that is why I perceive you ask about disc or v-brake.
While the old single pivot rim brakes never gave a great feeling of stopping power compared to other types of brakes, they generally are always good enough to stop in time.
Also, I find that my Shimano 105 5800 double pivot brakes stop my old Paramount much better than any rim brake I've ever had. And even slightly quicker than the Shimano Tiagra 4700 double pivot brakes that are on my son's Emonda. Although I'm surprised myself at that last difference. However the 105's do look beefier than the Tiagra's.
So if stopping power is the issue, maybe it can be more easily and simply solved by a better model rim brake.