Take your pick of any of those. But be aware that the Mosin-Nagant M1891/30 needs to be fired with the bayonet fixed otherwise the point of impact is vastly altered (unless the f/s is altered - the sniper versions have a longer foresight more centrally mounted than the inf versions for this reason).
Basically it’s whatever you fancy - remember to take into account ammunition availability and cost. Recoil-wise, the M1903 and Kar98k will be the worst, and accuracy will be best with K31, if you can shoot open sights well (although the length of pull on the K31 can be too short if you’ve got long arms). The No.4 is fastest to operate and certainly the best all-rounder
And btw it’s No.4 Mk I