Yuri Iwamoto wrote:humm, I might... *will have to learn self to draw rifle/gun*
If you need a reference Akai uses the L96A1 Sniper Rifle.
As for Amuro, it looks like he uses a P99 (Can't tell for certain since the manga doesn't really detail it that much.)
Also, to make things easier. You could just recycle the image/poses of Shinichi and Heiji on the mousepad you got by replacing the characters.
Shinichi would be Okiya with his left eye open holding onto his rifle instead of the book.
Heiji would be Amuro with his pistol and hand in his pocket.