Sounds kind of strange, but the World War II Museum in New Orleans has a travel agency and conducts a lot of overseas tours. Most are in Europe, but there are a few in the Pacific.
A couple of years ago, Mrs. Basket Case and I took the one that follows Easy Company (Band of Brothers) from training in Aldbourne outside of London to the Eagle's Nest near Austria. Covers D-Day, Market Garden, Battle of the Bulge and Easy Company's time at the Eagle's Nest. It's about two weeks, but they're packed. Could easily have made it a few more days.
Looks a little pricey until you consider that the significant majority of your meals are covered and include plenty of wine with dinner. If you've been to Europe you know how expensive even casual restaurants are, so this is a real selling point. We were several days in and realized we hadn't spent any money on anything other than souvenirs.
Point being, when you take all that into account, the price looks a lot more reasonable.
Excellent guides. Some are professional historians, many are local, all speak excellent English, and deliver information that's especially riveting when you're standing on the very ground where the event took place.
We spent most of an afternoon on the ground where Easy Company was getting bombarded through trees during the Bulge. It's fenced off now, beginning a hundred yards or so from the actual foxholes. So tour companies have to get special access.
If you're into World War II history, I highly recommend it.