I am very interested in Earthbound. I do not have any of the games you're looking for though. I would be willing to buy one and then trade it to you if you like. Is Earthbound complete? If so, I am assuming you would want the game in return complete as well.
I do have Mega Man X2 complete, that is pretty rare.
Forgot to mention I have doubles of Illusion of Gaia, Mario All-Stars, and Kirby's Dream Course as well.. obviously they wouldn't quite be a fair trade for Mana, but I'm open to other trade suggestions.