In reply to e.ms355:
A lot of the answers will depend on the weather... for example, Bishop is probably some of the best bouldering in the country but I wouldn't recommend going there in the summer.
A website I built could be helpful... www.climbcation.com is essentially a filter for world class destinations. Select bouldering as the climbing type, move the map to the US, pick the month(s) you want to go on your trip, and pick your bouldering grade from the dropdown to get your options.
Personally, I don't like going bouldering but I actually loved Bishop. If your trip is in the winter I would highly recommend going there.