While not entirely Commodore related, and it has a real slant towards the BBS/cracking scene, I really enjoyed:
Commodork: Sordid Tales from a BBS Junkie
by Rob O'Hara
First chapter can be previewed free on the authors website to give you a feel for it: http://www.robohara.com/commodork/
I bought it for my iPad via iTunes store and loved every minute of it.
Nice suggestion, Amazon has the paperback I see. Added it to the wish-list!
I just finished the second edition of Commodore : A company on the edge, looking forward to the sequel that details the post-Tramiel Amiga period...
Also I'm curious about Steve Jobs's bio, I pre-ordered before he left this planet... I hope it goes into history just as Brian's book.