As Zap points out, there are several variations in sff supplies- this one is also true sfx, with the airflow 90 degrees from the true sfx fsp model listed above...
http://www.power-on.com/microatxss200anv.html
So, measure carefully, be sure that whatever you buy is what you need, and that it'll clear the mobo and all the internal components. Some tight fitting sfx cases need a unit like this-
http://www.power-on.com/microatx270snv.html
Nice price on that Enermax refurb, if it'll fit...
Edit- Didn't open all of Zap's links- the one I listed first, above, is the same ff as one he listed, but I'm sure you get the idea... there are lots of other small psu shapes & sizes, too, of which the Power-on guys list several...