If I were getting a 300 I would get the WM not the WSM. If you reload you'll have a lot of advantages. It will be cheaper to shoot whether you reload or not.
Also the 300WSM is overkill for deer and it will matter. Wait till you see what it does to them. I learned my lesson. Too much meat loss.
I only use my 300 WM when I'm shooting long distances. Like beyond 300 yards.
For the rest I stick with the lowly .30-06. LOL.
Tom