It'll work. I use Qriocity for all of my PSN codes 'cause it's too much of a hassle to boot the thing up, download/install another patch, then use the on-screen keyboard to type in the code. The web site is so much faster.
You may or not be near any of these towns, but there are Food Maxx stores in Antioch, San Jose, Tracy, Hayward, Oakland, Redding, San Leandro, Sacramento, Union City, and a few other places up that way. Mostly around the bay area, it seems. Winco, unfortunately, is not nearly as popular.