These pages are not in order, I found them on Baidu.com. I wish I could read chinese, it is nice to see people doing Gantz-related comics/manga/doujin!:) Unfortunately I don't know the name of the person who did that and I can't do links here anymore, if someone who knows that person or the person himself see that please write a message!
That's where I found it, there are much more pages! http://hi.baidu.com/8488088742/album/%C2%FE%BB%ADgantz%26%2347%3Bminus