I have chased these critters for going on 23 years and better than 30 hunts this season and have had quite a few new guys join us for a hunt over the years with the same questions. I always start with the same answer; When you are in the Colorado Rockies and you don't like the weather, wait a half hour it will change. DO NOT TAKE YOUR CLOTHING FOR GRANTED; YOUR LIFE MAY DEPEND ON IT!
Start with a minimum 1000 gr boot. Trust me; on those morning and evening stands in Nov. your feet will still go numb. I have been very impressed with Danner Pronghorn socks. They are a Merlino blend and do wick the moisture better than any sock I have ever used. At times I change them during the day from heavy weight (morning & evening) to medium weight for the day. Don't skimp $$ on your footwear & socks or you WILL have a miserable hunt.
I don't know your camp arrangements; so I'm not sure if you can afford to pack heavy or light. But, I always tell guys to be prepared for the worst. You can go from hunting a bluebird day in a shirt and vest, to 2 1/2 feet of snow overnight. Plan out a good layer system for your clothing. I can literally go in one day, from hunting a motionless sub zero morning stand for 4 or 5 hrs to actively stalking the timber, which produces a lot of body moisture, back to an evening stand till dark and never return to camp to change clothes.
TORSO: Make sure everything, except your base layer, you buy for your upper body is blaze orange. So if you need to get idown to your lighter layers you are within the laws. Cabelas makes a Guide chamois shirt I swear by; it is vented in the rear and under the arms and has loops and pockets for many elk hunting essentials and, comes in blaze orange. Another great addition is the Cabelas guide vest that has a sewn in pack in the rear--works great to keep those outer layers not used. They also carry some great parkas.
LOWER: Nothing beats good old army surplus BDU's--lot's of pockets--While youre at Cabelas dont forget a pair of bibs.
BASE: Good old polypropelene long johns are great and cheap, but you do need a change for every day in the field. I do agree with mtelk Sitka is great stuff, but I do change mine out.
On a side note: buy and learn to use a GPS. For elk hunting, I have somany stories and accounts of how practical these things have come into play. I don't let anybody hunt with us unless they have one. And, a fanny pack with some essential survival tools.
Elk hunting is an extreme sport. I don't care if youre at 6K feet or 10K feet, 60 degree or -10 degree weather, man or woman. Over the years I have witnessed, heard and read so many stories of elk hunts gone wrong because of lack of planning, preparedness and ignorance. Be prepared for the worst the COlorado Rockies can dish out and you will have the best hunt of the year!
Good luck Mike