I just know Im going to get some flack for this...
1. Infantry rifle- Probably the M1 - if the Surm 44 isn't available.
Of course, that provides an entirely different ammunition logistics problem... and it depends on what kind of infantry I want to have, too (ones that can shoot, or ones that can not)? It all depends on my country's culture and military training.
2.Pistol- The 1911; I can't think of a better-suited weapon for the role. An M1 Carbine would just get in the way for officers who need their hands for other things.
3.Submachinegun - PPSh-41, working from the basis that a submachine gunner is going to be primarily tasked with providing moving cover fire, and an enemy soldier isn't going to care much if the bullet hitting him is a fast, .30 cal or a slow, .45 cal.
But the soldier carrying the ammo, probably will prefer the smaller bullets. And the gun itself isn't as heavy or awkward as a Thompson.
Alternatively, an M3 in .45.
I've no thoughts on the machine guns, other than that I'm undecided and conflicted. On one hand, the Germans (supposedly) had the best machine guns during WWII, because they were a large part of their focus. For us, however, they were an after thought; HOWEVER, JMB designed our's, which is a point of conflict, because we all know that JMB didn't design junk.