Sorry for answering this late.
So, here are my test results for the 300W SFX PSU that's in the Antec NSK3300 (will test the 380W PSU in the NSK3400 this week) versus a 80W PicoPSU with an 80W Edac power brick. You can also see what undervolting brings you.
I would advise a 120W PicoPSU though as the difference between 80W and 120W is negligible.
My estimate is that you can get another 15 watts off (at idle) by switching to a 120W PicoPSU and undervolting the CPU.
Thanks for that.
I did give undervolting a try, i can't remember what to (possibly 1.1v) and saw maybe 1w difference. Should i be doing this in the bios or with something in windows?
I'll give it another go when I get some time.
The picoPSU looks good, i think I'll pick one up, about Â£50 for that and a 110v adapter I seem to remember. I'll get either the 120w or the 200w depending on which is cheaper.
Unfortunately my internet connection is still down from the lightning strike so I've yet to use the damn thing, its pretty useless without any guide data.
Thanks a lot guys, I shall update when I finally get chance to finish it off.