If you want the Calixco Kitten, it will tell you which badge is necessary to obtain the kitty. You can visit all of the Faction vendors in Mirage to see which colors or logo symbol you might like the best.
My Ice is almost done with all of the Mirage badges, so she can get every mount, every banner, and every wand. My Ice has decided she wants the House Tabbi domicile because it's blue. She's also riding the blue House Tabbi carpet mount as well.
Take a gander at wizard101central.com to see all of the Mirage badges.
You can get all the badges for the faction vendors with no conflicts. You don't have to choose one. If you're wondering about the calixo kitten pet. I'm pretty sure you can buy it from the vendor without having to unlock it with a badge.