I have a Glock 17. Looked at G19 but didn't see it as being much different in size, and the grip groove spacing felt uncomfortable. I can't stand carrying IWB, so it's all OWB. I am also not skinny... 5'10 and 200 lbs so don't have much space between my gut and the belt.
The differences between the Glock 17 and 19 are significant and manifest themselves during carry...especially after a few hours.
One is at 2:30 or so, grip canted forward. It' easiest for me to draw, and it doesn't bother me sitting down (although sometimes I have to adjust it so that barrel doesn't dig into things & push the gun up). There's still a small amount of discomfort every now and then.
The most convenient way to carry, where it doesn't print at all and I can't practically feel the gun, is at 5:00. The problem here is sitting down, I end up leaning with my back on the grip. This is not an issue for a quick lunch at a restaurant, but I wouldn't want to drive for an hour like that.
You have made the case for the Glock 19. The problems you described are the EXACT reason why I dumped all my 17's. The Glock 19/23/32 solve these problems. The shorter slide prevents the gun from digging into the kidney or lower ribs when sitting in a soft chair or booth. The shorter grip also reduces printing when seated.
Dump the 17 and get the 19!
I guess my problem is finding a solution that works for all daily situations.
All situations = discretion = Glock 26. If you need a full grip, buy Glock 19 magazines and add A&G's Glock 19 grip adapter. This makes a bobtail style grip that provides support for the palm during shooting. Use the flat base 10 round magazines for increased discretion and the 15 round magazines when it's not needed (or you have extra clothes on).
So, what do you do when you carry a full size gun around, driving, walking, sitting down etc. ? Do you keep it on you at all times, if so in what location ? Do you take it out in the car ?
Glock 19 in most instances.
Glock 26 when discretion is required.
Given the financial situation described, I recommend you get the Glock 26. It is the one gun you can use for all situations. It is very accurate, offers very fast follow-up shots, and can take Glock 17 and 19 magazines.
Robar and other companies can
professionally remove the finger grooves for you.
Holsters:
Custom makers should be able to add extra forward cant to an OWB holster.
Look at Dillon Precision's Plan B for off body or car carry.
Magazine carriers:
Don't buy a double magazine holder. Buy two singles instead. You get some versatility and two singles conceal better than a double. The double is more blocky and doesn't bend to match the curve of the hip.