If it shoots well, then sure it is. The late Col. George Nonte, in his book Pistolsmithing, divided accurizing into two areas: Mechanical accuracy and practical accuracy. The former were about the mechanics of the gun; measures you could take that would improve group size if you were shooting the gun using a machine rest. The latter was about what makes it easier for the shooter to take advantage of that accuracy. So practical accuracy was about trigger work, better sights, better grips, etc. It sounds like you are already happy with your gun's mechanical accuracy, so if the McMillian stock makes a more comfortable an controllable way for you to hang onto the gun and keep the sights lined up with the target until after the bullet has left the barrel, then I'd say go for it.
The suppressor is a little different. I have no trouble with the idea in principle, but in practice you need to keep in mind the Savage barrels are not stress-relieved before contouring, so the muzzle may widen a little if you turn its diameter down and thread it for a suppressor. That can affect its grouping precision adversely, so no guarantees there.