I just read the "advice for new commuters" thread but still have some questions. I would much appreciate advice from the vets here.

Basics:

My commute will be apx 6 miles each way, mainly on residential streets with slow and moderate in volume vehicular traffic. One concern is my elevation. I live atop a large hill and there is a 700 foot elevation change from my home to work. Most of that is in the first mile, so on my way to work I will be going down the hill then dealing with mostly flat terrain for the remaining 5 miles and vice versa on the ride home. Timing is afternoon to work, 11 pm to home. I'm looking to buy a new bike and my budget is 500-1000$.

I'm looking mainly for suggestions on the type of bike I should look for including specific models. I want something that is comfortable but somewhat fast, and of course something that can tackle the steep hill on my ride home. Any other advice you may have would be much appreciated.