The G19 is like the F150 of handguns. Reliable and popular which is nice when it comes to picking out holsters and other accessories.Mags are cheaper than Sig as well.
If you can put together a Lego set you can completely take a Glock apart and put it together which is nice for cleaning.
Hornady makes some awesome rapid safes you can open with a standard key, code, or RFID tag. They are pretty great. If you live in Utah the state will give you $100 towards a safe if you have a carry permit.
Also these training barrels are a good thing to have when teaching kids about guns:
https://www.midwayusa.com/product/1015009248