I am going to go with the 338-Lapua if I can find it in a Sako TRG-S M998 Super Magnum action? I have been looking for this rifle & can not find it anywhere?
If you can't find a Sako that is already chambered in the Lapua you can always buy a rifle chambered in the .338 ultra mag and have it rechambered and the bolt face opened up to fit the Lapua. Like a remington 700 LSS which will probably be a bit erasier to find.
You aren't exactly going with an inexpensive shooter any how.