No these are not doujinshi, or fan mangas.  There two different  Kiddy Grade mangas. 

Kiddy Grade VS.  (right)
    Japanese 
    Illustration by: Arikui Fujimaru
    Story: Hidefumi Kimura
    Published by: Kadokawa Comics Dragon
Kiddy Grade Reverse  (bottom)
    Japanese
    Illustration by: Hiyohiyo
    Story: Gonzo/gimik
    Published by: Kadokawa Comic Ace

Both books are available at AnimeNation for about $9 bucks each, just type Kiddy Grade in the search box. No news about an official English book yet.
One of the differences in the 2 mangas, other than the artists, is that KG Verse seems a bit more comical than Reverse.

Studio ADTRW has Manga translations for a few chapters of both books, in Zip files. Definitely worth a look! (VS. and Reverse)

These mangas contain a few characters that were not used in the anime. If you view the chapters at Studio ADTRW you'll meet Dyne in Reverse. 
Alv and Dvergr play a big part in Reverse, and Twiddledee and Twiddledum show up in VS. 
Dyne:  featured in Reverse.     Virago and Viper in VS.
Smaller pics first!: