That pinky-finger extension on the magazine baseplate isn't going to help with an ankle holster. I know. I've tried it. Besides helping create more bulge, its also harder to raise the pant leg in a hurry to draw the gun.
If you opt for an ankle holster, first see if you can get a magazine without a pinky rest.
Oh, and hang on tight. Those little guns jump around in your hand. They're so light, even the minor recoil of a .380 makes 'em jump. The recoil isn't harsh; its that the darn gun is so small, its hard to get a really good grip. I don't have large hands, neither. The pinky rest will probably help, so you may want to factor its absence into whether an ankle holster is right for you.
Also, ankle holsters have two other draw backs.
1) The gun is clear down at your feet. Its not exactly a fast draw.
2. Ankle holsters need to be just a tiny bit snug--not loose and floppy. Meaning after several hours, you're going to notice the constriction around your ankle. And, since your calf is fatter at the top and tapers toward your ankle, the darn thing will slide down until the front bottom edge of the holster apparatus rests on the top of your your foot right where the front of your ankle curves and meets the top of your foot. More pressure, and slight rubbing as you walk.
Unless you need deep concealment, an ankle holster wouldn't be my first choice. If your clothes and situation allow, you might take a look at pocket carry. Just be sure to practice drawing from that pocket while seated or scrunched down behind low cover so you know what to expect.