Check out eBags. They have some pretty good deals usually. Coupon code "ENTBOK2008" will get you 10% off and free shipping. Use Live Cashback for another 22% (last I checked) cashback. And sign up for eBags rewards club (free) to get 5% of your purchase turned into a store credit for a future purchase.
I love the site, they ship quick, and have a huge selection. Take your time looking around though, their search feature leaves a lot to be desired. I somehow stumbled upon some canvas bags (search for Case Logic Canvas) that didn't show up on normal laptop searches. Most of their bags also have the laptop compartment's dimensions listed, which makes it real easy to ensure yours will fit.
I picked up two case logic canvas backpacks (15.4" and 17"), and 1 canvas messenger bag (15.4") (I have a lot of laptops), along with a camera backpack w/ room for multiple lenses, a single camera case, a laptop sleeve, a backpack for my girlfriend, a purse/messenger bag for my girlfriend, and a new travel duffel for myself, only spent about $261 total after all discounts were said and done, and now I have about a $25 store credit coming my way 😛
Oh, and I don't think I'll need another bag again. Ever.
As for coolers, just pick one up off Newegg that looks good to you. You can get something basic for around $20, or blow a lot more to get USB hubs, more bigger fans, aluminum frames, etc.