I agree- try Inghams for a week. Lots to do- huskies, reindeers, snowmobiles, Santa and learning to ski! Can work out much cheaper too than those days trips and short trips. Yes the excursions can work out expensive but so is Disneyland and this is far more beautiful, educational and fascinating!
Levi is probably more suited to you than Yllas. Not much in Yllas whereas Levi has more of a small town feel. Also you can go sledging on the main slopes whereas Yllas you need to get a ski bus to the hill. Both are lovely but Levi is our favourite as more for kids. Yllas is geared towards the more serious skiers.
Good luck! Once you've been ,you will get the bug. This will be our 7th trip to Lapland and we don't want to go anywhere else now. PS (Cabin/chalets/apartments work out cheaper than hotels and both Yllas and Levi have good reasonable priced supermarkets)