Sadly, I have both the unedited and condensed version of Rising up and Rising down, but I have only read the abridged version. I worked at the Strand for 5 years when I was going to engineering school, so I see 'Limited Edition' and wet my pants. Sad. The text is the same, but the multi volume version contains a bunch of maps, illustrations and case studies, that aren't really necessary to get his point. 'Whores For Gloria' or 'The Afghanistan Picture Show' are both sub 300 page Vollman books that are great introductions to his work.
As for comedy, no man is funnier than Philip Roth in 'Portnoy's Complaint'. That is funny stuff. That book makes my face hurt from laughing. This Dave Barry character I do not know.
'You Can't Win' by Jack Black (not that Jack Black) is also very funny, he was the original drinkingm, drugging, gambling scumbag circa 1904.