ISA in SBS - yes, it's secure
In his own words:
My name is Jason Fossen and I'm a consultant specializing in Microsoft Windows security. I regularly teach a six-day course on Windows security for the SANS Institute, including a course on ISA Server. This web site is where I share materials with my conference attendees, consulting clients, and anyone interested in Windows network security. isascripts.org
The scripts come packaged in a single zip file and admittedly most won't be of use to SBS admins but a few of them will be, like these:
Spreadsheet of names, descriptions and hex numbers of ISA Server 2004 error, cache and response codes.
View and edit permitted outbound HTTPS ports (see KB283284).
Download and be careful.