There is a site that talks about modifying the pattern such as lengthening the sleeves, adding a fold up collar etc http://www.knitting-and.com/wiki/Baby_Surprise_Jacket
It also points to where the pattern is printed.
Something of interest there is a podcast knit-along for the BSJ on http://yarn.com/s/podcast.html
You might get something out of it. No guarantee.
One more if anyone was stumped on the pattern where she says inc 9 sts (k3,m1) this site explains it in simple english http://www.web-goddess.org/archive.php/postID/6128
I just started a BSJ for a friend of mine that had the baby in June hopefully I'll get it done promptly (my knitting habit is what you would term flighty... like everyting else about me)