Wow. This is on the short list for "Best Funimation dub of 2014". Chris Bevins really turned it up to 11 on this one and, while the main cast was outstanding all around, Greg Ayres delivered a performance in this that should make his brother green with envy lol.
You don't even need to move to Japan or be in Japan at all to buy the merchandise… Just use sites like AmiAmi, Hobby Search, and HobbyLink Japan to import it, but be aware of shipping costs and potential customs fees when doing so. Animate USA also has some Karneval stuff I believe, so really, even importing isn't exactly necessary.