The original Kel-Tec pinky extension, IMHO, is the better design. There are aftermarket companies selling copies of it, but I think Kel-Tec has pared down its offerings of accessories for the P32 down to near-nothing because I'm sure they're likely planning to kill the gun off in the not-so-distant future as they did with the P11 ... which was basically replaced by the much newer P15. (Here's to hoping Kel-Tec has a better itty-bitty .32 ACP pistol design lined up, like maybe a double-stack and/or striker-fired P32, because the P32 currently has the market cornered on solid pocket-sized pistols in that caliber.) The original Kel-Tec +1 extension was also decent because it added a round and gave you more room for fingers, but didn't add enough significant length to the grip to make any real difference in its concealability.
Pearce makes a HUGE mag baseplate extension that is almost like two Kel-Tec extensions stacked onto one another. Makes the grip about the same length as it does if you add a 10-round extended magazine. It's ugly, it's completely overkill, it adds nothing to capacity (unlike the 10-round mag), and it's just plain goofy, but for whatever reason, there's more than one company selling knockoffs of the Pearce design, so I guess SOMEONE out there is buying them.
I would aim for either an OEM Kel-Tec extension or an aftermarket knockoff of that size/design, or better yet a +1 extension. Poke around on eBay, you might be able to score them there. Or, alternatively, buy one of the knockoffs of the Pearce design and then hack off half of its length and then smooth out the rough edges/corners with sandpaper.
EDIT: I just did a quick search on eBay for "P32 extension" and there are a SLEW of aftermarket +1 and +0 extensions by multiple sellers, and even a couple of +2 extensions, which kinda have me interested. Most appear to be 3D-printed, which isn't necessarily a bad thing, but some are traditional-molded designs, if one prefers. Garrison appears to be one of the major producers of the big-ugly-crazy-huge extensions mentioned above. Kinda tempted to order a couple of OEM 7-round mags and some of these +1 and +2 extensions, myself ... and maybe even, I dare say, take a chance on one or two 10-round mags made by ProMag (which are VERY hit-or-miss in quality/reliability) and adding an aftermarket grip sleeve onto it to make it like my two other OEM 10-round mags.
