Absolutely nothing wrong with the 300WSM, it will surely put the hurt on if you can place your shots correctly.
I would start towards the bottom of your list, pick up a good solid one piece base (20 moa will do), look in the direction of Nightforce, Badger, Leupold MK4, Seekins, Ken Farrell etc (not sure all of them make Savage Bases).
There are cheaper bases out there, but the ol' sayin of "buy once, cry once" really is where it's at.
You are already aware of needing a better optic, start digging through the classifieds, you can pick up some incredible glass for a song & dance if you're patient. You need to start with optics first, that way you will know which size & height rings to pick up. I really wouldn't bother with truing the action unless your rig doesn't perform, thats a +1 for the floating bolt head of the Savage.
If you are looking for heavy high BC bullets Look at Berger Bullets, JLk's,
Cutting Edge Bullets & Matrix Bullets, they all offer high BC, high accuracy bullets capable of dropping game. You will no doubtedly experience the biggest caveat, that being, with these long, high BC bullets, you will probably be relegated to a single shot.
Good Luck & keep us posted.