There is a grocery store on rue St. Antoine, the extension actually of rue de Rivoli as it approaches the Bastille. The grocery store is on the south sde of the street very near the St. Paul Metro and I think near rue St. Paul (a nice bakery and sandwich shop right on the corner of rue St. Antoine and rue St. Paul). Both of your apartment choices sound as though they are in a good location. I am personally partial to the Marais and I always try to stay there. From your St. Paul apt. you will be near Place des Vosges, many places to eat snacks and meals, and also close to Isle St. Louis which opens up another whole cafe venue for you. Be sure and try hot chocolate at Cafe Flore en L'Isle at the western tip of Isle St. Louis if you are staying nearby.

I think this area has more of a neighborhood feel than around the Pompidou.

Bon journee, Cathia in Austin