#1, I would recommend spending a few extra bucks and getting RCBS dies over Lee -- RCBS has a locking washer, which makes it easier to swap dies on the press without losing your settings. My seating die is Lee and I have to reset it every time, but RCBS you just screw in tight and go (assuming you set it right the first time).

For elk, I'd recommend going with a 180gr bullet for the WSM. Is your rifle a short action or long action? The one thing weakness of the WSM is that it needs to be in a long action to really shine -- with the longer bullets, you will either lose the use of your magazine if you seat the bullets out to use all your case capacity, or your chamber will be cut too short to seat them out. Either way, you will be left with sub-max loads. Custom gun guys like the WSM because they put it in a long action and throat the barrel for a longer-than-factory cartridge length and get 95% standard WM performance without the belted case.

Powders are hard to recommend, many work. I like Re22 but I have no reason to think that those given by others aren't as good.