few things to consider. firstl if you're going at a busy time like easter or october half term then its more a case of finding somehere the right size thats not booked up, rather than having any choice of area. if you've got an unusual number of peeps then thats even more the case. if you;re only going for a few days then forget about getting a gite as they only let them in block of a week frm sat-sat, unless they expect business to be extraordinarily slow at that time.
All the above withstanding, anywhere in the general area will be fine. most of the gites will either be around the milly/trois pignon area, or nemours/larchant/chapalle la reine, or near font town itself. there are some which'll come up on the gite websites which are miles away though, so always check on googlemap or mappy. every village has a small shops and there are supermakets in all the big towns, and a massive carrefour back towards paris (5 mins drive from cuvier) at villieres en biere. once you've driven however many hours to get down there a bit of a drive to the shops won't be a problem, especially if you're organised and don't need to ge every day. also remember its france so fuck-all is open on a sunday, and in the week the french lunch-hour lasts from about 9-5.