Left hand friendly guns? With exception of pistols that have a right thumb safety, almost all pistols are left hand friendly. I'm a southpaw and I have a Sig P220. I tried reversing the magazine release, but found I like it better when set up for the right thumb. I use one of my fingers (and don't have to shift my thumb) to release the magazine. There's no manually operated safety to speak of and as for slide release, I slingshot it with the non-dominant hand. Want to hear another advantage a southpaw has over any righthander? Failure Drill.
In a failure drill, you generally execute tap, rack, ready. With the rack, you rotate the gun such that the ejection port is facing down. Now, for a right hander, to rotate it that way they have to turn it clockwise, which is unnatural for the right handed person. So, most righties turn it counter clockwise. This works, but isn't optimal as the ejection port isn't 180 degrees reversed and facing the earth. For a southpaw, you automatically rotate it counter clockwise, and it's very natural for you. The ejection port is facing the ground and you're maximizing gravity in your favor.
Glocks work well for southpaws as do Rugers (Rugers tend to have ambidextrious safetys) and the newer S&W (the old 645 had only a right thumb safety and that's why I picked the Sig P220 over the S&W).
Wanna know something else about virtually any new pistol? It's a matter of practice to familiarize yourself with the gun. Practice, practice, practice. Being a southpaw isn't a disadvantage and when I was a young-one, I was trained DA shooting with a revolver (yep, I'm dating myself). I was in DA shooting (natural point) and my revolver would get so hot it was hard to hold when reloading.