Very nice. ^^ I like the black on Khalim better on the left but the color of Dante's skin on the right. His skin tone looks richer and a bit more vibrant on that one, but it also looks too bright between his cheek bone and brow line. Overall, I'd say the left.
As for finding the original image, try a google search. Try using different key words that you think should be about right or along those lines. Then if you know the original size of the image (just check the size in pixels in PS or something), you can do a search for the exact size on a google image search. On the image search once you're viewing the search results, click on "Search Tools," then "Any size," then "Exactly," and type in the exact size of the image. Sometimes that helps. ^^