Welcome to the wonderful world of Glock SJPrice. My primary carry for the better part of the last 2 years has been a 26 and before that my still favorite 19. I'm personally not the biggest fan of the grip extenders on the magazines because I'm wanting maximum concealability over the 19, but they do make the grip fit a little better. Instead of stocking up on 27 mags with extenders, you might want to consider investing in 23 or 22 mags. They work especially well as spare mags for carry and range and give increased capacity and a little more grip if you choose to use it as such. They also tend to be the same price as the smaller 27 mags.
Any idea why the .380s are LEO only? That just seems weird as its not a common LEO caliber. I mean, even for a bug, there are 9s and .40s almost as small. And why restrict it unless its FA like the G33?
FQ13
As Solus said, they don't meet the import criteria. They are mainly designed for countries were civilians can't own military calibers firearms. More importantly, I don't see a real market for them in the US other than collectable. To my knowledge, all .380, 9mm, .357, .40, and .45 GAP glocks are built on the same frames/dimensions (obviously 3 sizes in each category). The primary advantage of most .380's is that they are small, light, and concealable. A .380 Glock would offer no real size, weight, or capacity advantage to a 9mm. I don't think there would be any cost advantage to shooting .380 either.