IMHO it doesn't really matter which GFD you have, though you have to see wether it's userfriendly or not. GFD's without the need of external voltage are easyer to use. Small ones are better then big ones, which obstruct airflow in your case.
http://www.tech-report.com/reviews/1999q4/gf-card/gf-1.x
(some info on a card, also good case cracking links on the first page)
http://www.tech-report.com/reviews/2000q1/gf-roundup/
(GFD roundup, what you've been looking for)
Some of these links may not show the most up to date versions of GFD's, but you'll get the idea.
Succes,
Murphy