usa/canada/alaska roadtrip

Hi
Would just like to start by thanking you for any advice you may beable to give me.
I am planning a snowboarding roadtrip with some friends starting around december at the end of the year (2009) beginning in Los Angeles. I was thinking of driving up through california, to mammoth mountain, continuning on through oregon and washington, to seattle, crossing into Canada and going to whistler. I was then thinking of driving up to Valdez alaska as I have always been intrigued by the beauty and the mountains. Was then thinking of heading back into canada, driving through banff, back into the usa, into montana, wyoming, idaho and utah, heading through las vegas and finishing in los angeles. The intention is to stop at lots of snow resorts for a day or two at each and see lots of the country and mountains. i would probably allow at least two months to do the trip. Just wondering if anyone could advise me on any great locations to stop at. Any one know of a great place where you can rent a snowmobile? Some advice on the type of vehicle to do a trip like this would be much appreciated. I was thinking of buying something like a dodge ram 2500 and renting a small 5th wheeler/ caravan to tow behind and sleep in. Any advice on buying a vehicle in the usa and selling it at the end of a trip would be great! Also are the roads that far north open at that time of the year or are many highways closed due to snow?
Any help or advice is very much appreciated.
Has anyone done a trip similar?
Thankyou!!

Since the 2010 Olympics are in Whistler in February have a close look at your options-there may be little space and super high prices.

Lots of other places in the Interior of BC though.