Since I don't know much about the hotels, I thought I would fill you in re: some of the possible ways to tour the battlefield, and must-see attractions.
A great to see the entire battlefield is to hire a park guide to ride with you in your car. It's around 40 bucks, and they drive your car for you so you can see everything. They will get you out of the car at least 4 times, and can gear the tour to your interests. They know SO much about the battle, and it's really a great way to tour. If you are seriously interested in this option you should try to get to where they sign out the guides when they open. The guides are self-employed, meaning they show up when they want and sign up to go out on tour, and so they operate on a first come first served basis. For example, you could get there at 10, and pick up a guide at that very moment, or not be able to get a guide til later in the day. You take your chances with this option the longer you wait.
You can also take a bus tour with a guide which also provides a nice overview. Another option is to buy a CD to play as you drive yourselves around the battlefield.
The new visitor's center is awesome. Check out the National Park Service website for more info on that. They have great ranger-led walking tours - 2 that I would recommend for first-timers are the Day 3 tour and the Nat'l Cemetery tour. Just pick up a tour schedule at the ranger desk inside the visitor's center. All ranger-led programs are free and are well worth your time.
The Schriver House is great - it's a small museum that a family has refurbished to look as it did at the time of the battle. It's worth a trip - it would probably take about 30-45 minutes to tour. It helps put life in the town in 1863 in perspective.
Hope that helps. I'd be happy to answer any other questions you may have!
