I know exactly the one you're talking about and have the entire series at home.
Joel Rosenberg is the author.
The series is "The Guardians of the Flame
The first book in the series is "The Sleeping Dragon."
After checking out the link it appears I only have the first half of the books in the series. Mostly because it got pretty bad by that point.
Hmm, after reading all the way through your post this may not be what you are thinking of but it sure sounds like it.