Hey, I know it's been a while since this thread was active, hope I'm not necroing something dead, but:
All airsoft pistols I use are gas operated; since they're not getting heavy duty in milsim ops (like my M4 is), the gas works just fine, especially since you're mainly using it for last-ditch CQB (close-quarters battle) situations.
I prefer the gas over say, AEG (electric) or basic spring pistols. That doesn't mean the others aren't good, just my preference.
Tokyo Marui is one of the best Airsoft manufacturers in the world; their items are amazing.
As for 'high end' being gas or electric (AEG), it depends on the manufacturer. For my M4 and my M249, I stick with AEG...much more upgradeable and I like how they operate, but again my pistol is gas. Less chance for electric components to go haywire
Some great vids and products over at www.airsoftgi.com
The frontman, "Tim", gives excellent gear reviews. Take a looksie