Although Kotobukiya's brand-new, 1/12 scale Mega Man X model kit isn't due until August-September, it couldn't hurt to place a pre-order now. Here's a few places you should check out:
- Big Bad ToyStore
- Hobby Link Japan
- Koto US (official Kotobukiya US store)
- Ami Ami (Regular Edition | Ami Ami-Exclusive w/acrylic stand)
- Play Asia
- USA Gundam Store
- eKnight Media
So that's where we're at right now. More retailers will carry X as time marches on, naturally. But if you ask me, you can't go wrong with Big Bad ToyStore and Ami Ami. Both are great.
Also, it does indeed look like international retailers won't be offering Kotobukiya Japan's exclusive background. I was hopeful that at least Koto US would offer it... but alas. We're out of luck for now. Worse comes to worse, you could always make your own?