Which arrondissement in Paris? & clothes

Draw a line between those 2 places and it goes straight up Bd St Michel, which splits the 5th and 6th arrondisements. A hotel in either one would work for your purposes, but I'd look for one with a Metro stop within a couple of blocks. We've stayed a few times at the Hotel des Grands Hommes, which is on the same street as the Pantheon. Have a look on booking.com for hotels in your favored area and within your budget.

When you say pants for work, do you mean heavy duty work pants, or pants for office use? Not sure how easy it will be to find cotton/linen blends in October. The stores should be full of winter wear by then. Maybe the clearance racks?

Clothes: Galeries Lafayette have both high-end and mid-priced men’s clothes and their selection is pretty incredible. My husband generally shops there when in Paris. He never fails to find something cool.

That said, the city is LOADED with options. If you want to brave a mall, head for Westfield Forum des Halles. There are tons of shops there at many price points, and I don’t think you’ll have difficulty finding something you like, in your price range. As a bonus, it is just a few blocks from le Centre Pompidou! So you can check that out, too.