1. Longer sight radius, which should result in better accuracy. I've heard of some people shooting compacts better than they do standard pistols, though, so mileage may vary.
2. Higher capacity. This point may be moot depending on NJ's laws, I can't remember if there's a 10-round limit on magazines there.
3. Higher weight, which should reduce felt recoil.
Based on these points, and assuming you never plan to CC, I'd recommend a standard sized pistol. However, especially considering your age, keep in mind you might end up moving, and might have the opportunity to CC after all. It would be frustrating to have a gun too large to conceal easily...of course, you could always get another one if/when you hit that point.
I know you stated that you can't handle any handguns at the shop, but if you have any friends that shoot, the one thing everyone on here would recommend would be to try out a few handguns to see what's most comfortable for you.