Hi Michael, I think it's safe to say that many/most first time visitors find the 4th, 5th, and 6th Arrondissements to their liking-they're central, and they're near most of the key sights you want to see. If markets are a priority for you and your family, become acquainted with what happens when and where, and let that be your guide. It's worth noting that via the Metro-or bus-you can get around the city fairly easily. It takes time, sure, but there's so much to see on the way. Great cafes and restaurants are in every area, and the Metro is usually not far away. Our first time in Paris we stayed near the bottom of rue Mouffetard, a market street (not to be confused with markets). It was fabulous, it's all fabulous.
Don't feel that you need to be in the 4, 5, 6 to have a great time, there's the 10th, or the 14th, so many great neighborhoods and each has its own vibe.
Here's a link to a list of markets, and some photos of our first trip; see what hoe's your row!