I went the backpack route. After a couple weeks researching I finally made a decision and the bag arrived last night. It's a Targus Pulse (model #RG0315c - Targus bags with RG in the model # incorporate some Rakgear components) and the best deal I found on it was at buy.com for $30.04 w/free shipping. It has a built-in sleeve for a laptop which I am using to hold the case which contains my mics. It has several other sections and many pockets including one that holds a jb3 perfectly. The 14.5"x11"x18.25" dimensions give plenty of room. It also has thick padded, ergonomic shoulder straps and a waist strap for distributing the load.
The Targus
website has basic info, and there's a review
here.
If you want to go a little bigger, check out the Targus Matrix, model RG0322. I also considered:
Ultimate Direction 'Freelance'
REI Alpine pack (3100 cu and currently at REI Outlet for $34.93)
Lowepro EX1300. Others here say if you're buying a Lowepro, get it from Photococan - an eBay store.
I believe the original Mountainsmith Cairn and Blaze have been discontinued and replaced with the Cairn II and Blaze II. I couldn't tell you the differences, but
Campmor carries them.