Yes I like 9mm, I have 6 that I can recall of the top of my head, relatively inexpensive to shoot, if you can find some these days. The ones you've chosen are reliable and Sigs, although not my favorite are usually more accurate than the Glock, but then again, the 19 and 26, usually shoot better than the 17, go's against common thoughts on shorter barrels, but I've seen it again and again. I had a 19 that shot 1 3/4" at 25, and I will take that all day long, had a 17l, that would only do 4", go figure.
Did your salesman, tell you he would have to turn in a multiple handgun purchase sheet to the ATFE? It's no big deal, but when I sold guns, I would let the customer know that, and they could come back a different day and purchase and I would not have to do that, it basically puts you on a watch list, for purchasing handguns for resale or straw purchases.
The milks been spilled, so no going back, just did not know if you understood that.