Here is some good info on the 'upgrade' for the 2nd gen G19:
www.thegunzone.com/glock/upgrade-faq.htmlI have a a 2nd Gen. G19 and I like it a lot. Three-letter serial number prefix, so I am good to go.
Armorer's manual can be found online for free, spare parts are at CDNN and other companies if you want to get some of them as backups.
Only downside: stock plastic sights suck (weak, esp. for one-handed slide racking in extremis). I looked around and decided on the Sevigny Carry, a very solid steel sight set with tritium fore and aft, like a Heinie Straight-Eight.
Anyway, I would just replace the sights with something that you like, and you're good to go. This is a pistol that if you drop/throw/etc. you won't care about too much, as all Glocks are really the same; there's a guy selling one on the EE here for $350, and if I had the cash, I'd buy it!