I would wait and see if they do that racing pack for the US as well. I got the GT3 racing pack when it came out - nice stuff. If this one comes to the US I'm going to get it as well.
And about your power issue - every country around the world has a different power standard. Both the connector and the power output. But since this is such a common problem, it's been well addressed. There are lots of options - check companies that provide travel supplies. Make sure you get one that goes the right way - plugs Japan into US.
Japanese electronics function completely fine in the US. Same everything. You won't have any trouble running a PS2.
Japanese appliances, on the other hand, are different. This means ovens, fridges, etc. Not something you'd be importing unless you REALLY wanted to be "JdM tYt3 y0!"