Get whatever one seems like it will be the most fun to you.
Mausers have tons of variety, from action types (89,91,93,95,96,98), to configuration (carbines, short rifles, long rifles), to caliber (more common calibers like 7.62 Nato, 30-06, etc, common calibers like 8mm Mauser, 7mm Mauser, 6.5x55, 7.65x53, etc, and rare calibers like 8x50r, 8x52r, etc.).
Lee Enfields have a little less variety, calibers are generally limited to .303 and 7.62 Nato. They also tend to be in the short rifle configuration only (yes there are carbines and long rifles, just not even close to the same quantity as the short rifles).
K31s are well K31s, not much variety in them. Beautiful rifles though, which I absolutely love (I possess most Swissrifles from 1889 to the 1950s).
Also I wouldn't really consider the M98 Mauser the apex of the bolt action, the only reason it is still a popular action is because it can handle higher pressures than most the alternative actions which matters more for the sporting community then the military community. It became the most popular rifle for a while more due to marketing and luck then anything else (Mannlichers were popular alternatives until after WWI, when Steyr wasn't allowed to produce firearms for foreign markets, that left Mauser rifles only and even then not GermanMausers rather FN and CZ produced rifles).