I'm making a Kirby fighting game. I need some recommendations, such as a good game builder to use. Mine's really crappy

. I'm going to use Kirby Super Star sprites, as they would look the best in a fighter. Here are the characters that I intend to have:
Kirby
Meta Knight
King Dedede
Bugzzy
Birdon
I could use some suggestions, such as: What characters do you want to see? What levels should I use? Anything will do.