Yea I like having my hoods on just for the protection
he's talkin about focusing on the subject...

I'd go with the Slingshot without any hesitation, if I could fit all my shit into one of them. By the time you get to the Slingshot 300, you might as well get a regular pack. And $67 is a good price. It'll protect your gear, and keep it accessible whenever you need it. Most of the bigger packs are north of $200.
Can someone please explain to me that my SB600 is extremely versatile and I really don't need to buy a second flash. Sometimes looking at the Strobist stuff is demoralizing because they have a ton (read: $$$) of equipment!