Be prepared. You have just been infected. It is irrelevant if the other dealer will refund your money, because now that you have a 19, you'll "need" and 17, and then of course a 26.
I'll save you some time:
- Vanek trigger (or the .25/quarter trigger job at least)
- Dawson, Sevigny Warren or Heinie sights
- Hogue grip (or, 'yes, you can file down the finger grooves' - large numbers of Glockers do one of these)
Lone Wolf Designs, Glockwork, Glockmeister, GlockWorld...there's a starter on the bits you will want to get.
The complete strip and reassemble that you are dying to do can be seen on Youtube - there are a couple of outstanding videos, you will do it tonight if you haven't already, and you will have officially succumbed to full-fledged Glock disease.
Glock Talk will be your next forum.
Cheers - enjoy - I was an anti Glock, too, until I decided that I'd rather spend $500 on something I can customize easily and cheaply and reliably instead of $2000 on something finicky that I HAVE to dump money into.