Large backpack/case for MBP 15"

Hello all,
I have ordered myself a 15" 2.2ghz MBP and need some advice for a bag to buy. I am going to buy a USB-Microphone interface (like the m-audio Fast Track) a small collapsible boom stand and a microphone and create a sort of mobile recording studio. My girlfriend and I are both trombone players and are often asked about recordings for competitions and such, so I think besides being able to make some money recording other players, I can use this setup along with garageband to put together some recordings for myself. Here's my problem:

I need a bag that is large enough to hold everything (nothing is terribly large so most backpack and larger bag style cases should be fine) is very sturdy, and provides a lot of protection for the computer. For mobility I have been leaning towards a backpack style case but i've never owned one so I don't know what to look for. Basically I'm hoping for some suggestions for specific bags that are of good quality, have great protection for the laptop, are comfortable to wear, and have enough room for what I need, but are not cumbersome.

Thank you for any help.

 

The Samsonite Urbanite backpack is an option, as is the Samonite L45 messenger bag.

 

Swiss Gear Maxxum
Red: http://www.newegg.com/Product/Product.aspx?Item=N82E16834996915
Blue: http://www.newegg.com/Product/Product.aspx?Item=N82E16834997084

I own a Swiss Gear backpack very similar to these (you can barely tell the difference) and it is exellent and has plenty of space. The reviews say it all.

 

If it's the budget, take a look at the Tom Bihn Brain Bag. You'll need to buy a monolith or brain cell too but that backpack is absolutely HUGE.