Questions On Holsters and Sidearm Pistol?

Well now that i'm buying my first sniper rifle I realize I need a trusty secondary weapon and holster. First of i'm just wondering about everyone personal preference on this one. If you guys could maybe give me some good reccomendations on a drop-leg or shoulder holster, please tell me which one might be easier and what you might use. Secondly I am going to need a good Gas Pistol to fit in that holster At the moment I am looking into the Mayhem GBB by Gameface Airsoft. If anyone has owned this weapon please tell me what you think of it or if you have any other good reccomendations. All answers will help, and please know that everyone help is greatly appreciated. Im just getting into airsoft sniping and this forum has helped me so much. Here is the holster and pistol I am looking into now.

Pistol: http://www.pyramydair.com/s/m/Game_Face_Mayhem_CO2_Blowback_pistol/2300

Holster: http://www.pyramydair.com/s/a/UTG_Special_Operations_Universal_Tactical_Black_Leg_Holster/740

Please tell me what you guys think or if you have any other reccomendations. Thanks