Welcome to AA! You'll definately learn from the best...
I just started here a couple weeks ago (complete newbie to any fish... now I'm in love with goldfish) and I've been able to make up for my mistakes, and am establishing an awesome tank
You're so smart to do your research before hand... I wish I did that
Oh well, live and learn.
So I'm not an expert, and don't know much about community fish yet, but from what i've heard, if you want an aquarium, long ones are better than tall. Most fish would prefer to have more surface area to swim instead of swimming up and down. I could be wrong but I'm pretty sure thats right... And that way you can stock more fishies
Be greatful you have a petsmart, I live in a small town where the biggest tank I could find was a 60gallon. I'm going to need to special order my tanks from now on
anyways, good luck and happy fishkeeping
I'd recommend posting your questions under the getting started freshwater forum