It's a nice jacket and certainly better looking than what most Parisians are wearing at this time of year. RL is much appreciated over here so you won't look out of place. Plus it appears to have plenty of secure zipped pockets which will keep the inevitable Metro pickpockets at bay (Les Champs-Elysées have become quite bad for petty crime, mostly aimed at tourists, in the past year. Yet another reason to avoid what the French still insist on calling "the most beautiful avenue in the world").
Rue Marbeuf is the most SF-approved shopping street in the area you've selected. Berluti, Canali, Corneliani, Zilli (only joking), Cifonelli RTW (and their bespoke operation along the street), John Lobb (on a sidestreet off Marbeuf), and a really good branch of Arthur and Fox (men's weekend / classics / Boglioli). There are a few decent brasseries and cafés on and around the street (the further you get from the Champs-Elysées the better for value and atmosphere). They're nothing special for foodies but if you want a beer and a steak frites between shopping and sightseeing they'll do the trick). You also get to hang out around some of the well-heeled Parisians who live and work in the neighbourhood. I like Café La Belle Férronnière, Rue Pierre Charron just opposite Lobb's. I stress, nothing that will trouble Michelin but very much where locals lunch during the week. There's a Maison de la Truffe nearby, which is expensive but fun if you like truffles.
More SF-inspired fun: Not far from Place de la Concorde is a Slowear (Incotex, Montedoro) boutique which is worth visiting.
Note that you're getting in on 30 December: Much of Paris (and indeed France) closes on 1 January so make allowances for that. Enjoy your trip!