For a huge selection and great - perhaps the best- prices, check out Campmor
. You can order their catalog there too. Bare bones black and white catalog, unlike the 'big' guys, but that probably helps hold down prices.
Boy Scout troops are not exactly fountains of money. This is where we get a lot of gear for our troop because it is the most affordable.
If you definitely want to go to a retail store to buy, you might consider one I didn't see on the list above - Bass Pro if you are lucky enough to have one nearby. I've found them to be the best cross between Cabela's and Gander Mountain - Cabela's selection with Gander Mountain pricing. At least the last time I was there. Unfortunately we don't have one close out here.
Whatever you end up doing to get gear, don't let anything keep you from taking the family out and enjoying the great outdoors!