I think you should definitely go with PUB - I LOOOOOVE THIS WORKOUT. It is an awesome workout and I always feel it the next day. Besides by adjusting the weights, you can make it as easy or as hard as you like. Also, it has great ab/core work.
Otherwise you may want to try Bootcamp which is has been great for my obliques. Better yet, get Ab Hits with several ab routines.
Hope this helps, Wendy