Sounds like Northstar-at-Tahoe is your spot. It's had a reputation as more of an beginner/intermediate mountain for as long as I can remember (although today, I'd have to say there's a really great variety of more advanced skiing especially off the backside). There's a base village with a concentration of restaurants, shopping and other activities providing diversions from skiing. And the lodging delivers 5-star experiences all the way. The new Ritz is right on the mountain, there's a Hyatt in the village and great upscale condos, if you're looking for more of that style too.
On the ski school front, my kids have done both private and group lessons and been very happy. Just saw something on the news last night about their new bump skiing terrain that's designed to help people get quicker into the sport and improve rapidly. Looked very interesting. My father-in-law rented all his gear at the base village shop last year and they were very helpful, quickly swapping boots that didn't quite fit after a couple of initial shakedown runs.
Here's the link to their website www.northstarattahoe.com. We used Tahoe Mountain Lodging in the past to arrange condo rentals in the village and they're great. Northstar also has a very convenient shuttle that runs all throughout the homes in the area, so if you have a larger group don't hesitate to rent a house. The shuttle makes it possible to get easily from the house to the slopes in five minutes.
Now that I've talked up Northstar, it's obviously not your only option in Tahoe. Squaw Valley and Heavenly probably provide the next-closest matches to your criteria. I wouldn't consider Alpine or Kirkwood at all. The skiing is great at both locations, but the choices of lodging and other activities is very limited.
Let me know if I can help you with additional information.
Matt K @ GearGuide