Go for the delux if there's any left. These things are great. They'll cut down your knocking in time by about a third plus you'll get less arm ache.
The regular mallet is fine. I've knocked in plenty of bats with these.
The "ball-on-a-stick" isn't as useless as people tend to say, although you probably shouldn't use it on its own. These are great for testing is a bat is knocked in properly ready for use. If you're not leaving seam makes when you hit your bat with it then you're good to go.