Here, you look for a dark brown (like earth brown color) and white. The white will be your front because that's his stomach. Make sure that the front neckline of the body suit is white and not brown. Just because you practically don't see it most of the time, doesn't mean that it's not important!
Once the body suit and the stretch pants is completed, then it's time for the paws and the paw feet. Scroll back up for the website and follow those paw and feet paw instructions. The only difference is that you add four toes and not three like Persian. So that gives all four fingers, excluding the thumb, to be independant toes. For the paw feet, all you do here is add four toes and pay close attention to the coloring of the feet because his toes are white and not all the way brown.
It's always good to go the extra mile by adding paw pads underneath the paws and paw feet. This just gives it an extra "umph" to your four-legged creature cosplay. Only do this if the four-legged creature HAS paw pads.
Now, since he has a little mane, my strong suggestion would be purchase a Cheapy-Spike wig (dark brown) from:
Or at least a Tina Turner-like wig (brown or dark brown, depending on the shade presented best), and style it into the human form Sora hair style with a tutorial. Study how big, long, and what shape the ears are and then sew them onto the sides of the wig after you style the wig.
Whatever cut off wig you have left, then make those the little spiked hair part on his tail. In this case, his tail would be a semi-plush tail, meaning it's not fully plush, but has that little plush feel to it.
For all tails, make sure that you handstitch the tail where you want it on the back. (A little above the butt area is perfect). This is so that you won't have to worry about your tail being on straight while trying to have fun at the con.
As for the Kingdom Hearts Crown necklace, that was bought at a con in 2007. Talk about luck on my part^^ If you can, try to find the necklace already made (now, mine has real chains, so it's got some weight to it), then get that first and see how that works. If you can't find one, then be creative in creating the Kingdom Hearts Crown.
Just a fair warning about this particular cosplay. If you wish to do this cosplay, then may God be with you because this was one of the most challenging cosplays I've ever done. Please go all the way by creating (or purchasing a good quality) Kingdom Keyblade. Here, I created mine from scratch because not only was it a challenge, but also cheaper.
Here was the ending result of my Pride Lands Sora Cosplay: