Hello, I'm looking for a possibly new carry pistol. I need it to have an ambidextrous slide release, safety and magazine release. I am ambidextrous, but I favor my left side and want to carry on that side, right now with my XD and my beretta I have to switch hands to reload or change my grip altogether and it slows me down when I'm practicing my quick reload. I know an HK is probably the closest I'll get, but if there is one out with everything on both left and right side that would be great, without the price of an HK. Thanks!
Try the S&W M&P in .40 S&W, .45 ACP, or 9x19mm. The slide release is ambidextrous and the mag release reversable. Most lefties I know and those who have shot my M&P 40 use their index finger to release the mag and do it as quickly as I do with my thumb. Otherwise it is a lower cost option for ambi use than the H&K like the USP40 that I have as well. Mag release is reversable as well so you can make the LH your strong side with the thumb operation as well.
Not sure about which HK you mention, but the P7PSP is not highly expensive, and is the most ambi pistol I know of. It is also commonly regarded as being the most reliable auto ever made. The mag release is on the bottom, and the only other control is the grip lever which both releases the slide from the open position, and cocks the action. The newer versions have a double-sided mag release behind the trigger, but those versions are kinda pricey.
A cheaper pistol to consider is the Walther P99. The mag release is on both sides of the trigger guard. There is no safety lever to mess with. Slide release lever is on the left, but not an issue if you rack the slide. The P99 is a great pistol, easily as accurate and reliable as a Glock or XD, but also has wonderful ergonomics and an interchangeable backstrap.
The CZ85 Combat has ambi slide release and safety levers, and I believe that the mag release button can be reversed.
I'll second the Smith M&P's. I have the 9mm fullsize and it's been a great, reliable piece with no malfunctions at all. I bought it as my first handgun because I'm a lefty and it was the most lefty friendly model I'd seen.