From Someone Living in Paris for 20 years-
Hello, I just joined this group, and i see you are going to be in paris for a week, maybe you've already come and gone or maybe you are here or your trip is coming up.
For preparing stuff on your own, i don't think you need to bring stuff from home, there are many natural food stores in paris, most notably a chain called "naturalia" that is really all over the place:
29 shops in paris alone and paris is not large, geographically speaking. that means walking distance from most places. most shops are open from 10am to 7:30 pm monday through saturday. of course you can also buy rice etc.
in monoprix grocery store (sometimes combo-groceries and department store) also all over the place, they have a small natural foods section "rayon dietetique" with a very small selection of gluten free bread, cookies, etc. you can also find rice cakes in almost any groceries stores and most good size grocery stores have a "rayon dietetique" but you may have to ask to find it. they're hard to find.
a typical french restaurant will have an option of meat/fish/poultry plus vegetable plus starch: potatoes or pasta or rice.
it's not unusual to have broiled fish or meat as an option. i eat out about twice a week and i can almost always find something.
there are many many chinese takeaways and japanese sushi restaurants, where you can get miso soup salad and some meat and rice.
these are helpful if just out and about and suddenly hungry. grabbing a couple of spring rolls: "rouleau de printemps" at the nearest chinese takeaway can be a life saver.
as for the SARASIN crepes, it is true that that means buckwheat and most savory crepes in a restaurant (but not on the street) are said to be SARASIN(buckwheat), but i don't know if it's pure SARASIN or not. If you don't speak French well I recommend writing down the key words and showing it to waiters, etc, as french pronunciation is really sometimes tough in the beginning. the nice part is that many many people especially young waiters and waitresses speak english and like to speak english, now.
In naturalia and elan nature you can get some nice gluten free fresh baked breads most of the time. my favorite was a combination of rice, quinoa and chestnut flours found at elan nature.mmm.
if you eating at someone's home tell them in advance, and explain, as most people do not have a notion of what is gluten free. if you are invited to someone's home spontaneously, still explain and hopefully you can make do with meat, cheese, veggies, salad and all the rest. there are lots of dairy products in france, so if you can eat cheese, you should be ok.
oh yes, just about any restaurant will make you an omelet if you request it and in any case it's usually offered at any caf