The newegg.com 400W power supply is not only powerful but pretty efficient. The output is very good for a 400W AT power supply...
+5V@32A,+12V@18A,-12V@0.5A
Compare that to what's shown on your current power supply. Factor in that it's new, reasonably priced and should be plug & play and I don't see much downside. I haven't purchased mine yet so I can't comment on quality or fitment issues but they "should" be fine.
