Mike,
I hear you on the chore of shopping around for paper. I hate walking into large office supply stores and trying to scan the entire shelf which never seems to have the order of division that makes sense to me. I imagine you're looking for a glossy finish since it's brochure printing so you might try one of these two options.
1st: If you call Office Depot's 800 number, they offer a very heavy (over 100 weight) paper with something like a 94 brightness rating. This is probably overkill and would also be expensive, but it lets you know that there are heavy options out there. my local store doesn't carry it, but you could order over the phone if you wanted (most likely you'll find something a little thinner you like). I'm pretty sure they have some 67 lb. paper as well with a glossy finish. Before you buy though, check with local print shops and see what they'll charge to fold the brochures. The paper I'm referring to is plain (non-brochure) and doesn't come pre-folded. But this is how most print shops operate and they will have the equipment to fold it professionally so no one will know the difference.
2nd: When you're calling the local print shop to check on folding options, ask what paper they offer and just see if they'll sell you some blank paper. A good question is to ask if any other customers have put in special paper orders that left the print shop with a stock of paper they normally don't offer to customers. You may luck up and find the right weight and gloss and if you're really lucky, it'll be some light shade that will work well for your brochure.
Good luck,
John