There are some new 98 Mauser actions built today, both conventional and square bridge, but most are built off older Mauser actions. Zastava built actions used in the Interarms Mark X, some Parker Hale and some BSA. After WWII, Brno built the Model 47, which is a great action, and FN built actions used by Sako and Browning. These are also superb. CZ made the commercial ZKK600, 601 and 602. Husqvarna built a bunch of nice Mauser-based sporting rifles. There are a lot of older custom rifles of various stock quality, and Sako and Browning rifles, which would be less expensive than the action alone is worth.
Some very solid military Mauser actions which make nice sporting rifles would be the Czech VZ24, the Argentine 1909, the Persian Mausers, the Yugo ( Zastava ) 24/47, and the Yugo M48 ( made up into the 1980s). The M24/47 and M48 can be found in military rifles which are in unissued condition, for about $300 USD now ( and $120 just four years ago).
Granite Mountain Rifles in the USA produce a very high quality Mauser 98 action. There are also many, many makers of 98 actions and custom rifles throughout Europe and the USA. I'm sure your book research will provide you with a huge amount of information relating to makers of Mauser 98 actions, both historical and current.