Mini-iTx power troubles.

Hi, I've been building this Mini-Itx (media) rig and may have planned wrong ?
I've never built one of these before. The whole idea happened when I spotted these perspex cases very cheap.

Struggling with power for :

HP Locktite-GL8E (otherwise known as an ASUS IPILP-AR)
E6700 C2D
DDR2 667 (2x 1Gb)
1x 120 Gb Toshiba 2.5 HDD
1x Slim DVD-RW
2x 60mm Fans
Front LCD Display
* also would like to add a HD5450 low-profile for HDMI

I can't seem to get a PS estimate of under 240w (current of up to 12A)
Will this Mini-itx PS unit (OT540) 12v 200w cover it, you think ? I can't find any PicoPSU's with 250 or 300w.

In hindsight I should have went for an atom or something less 'draining',
as the whole idea was to have this case with no 'chunky' PSU.

The system is built and currently fine with a 400w ATX attached.
How do I get around this one ?

try without the 2 fans... you may be able to get by with just the cpu fan, failing that, look into cheap Solid State Drives. And defiantly scrap that DVD drive, I've just shared a BR drive on my network and haven't run into any problems. You could also get a single 2GB stick of RAM... any or all of these things could lower your power/current draws. Best way to tell is start unplugging stuff until you boot properly.

Check out SPCR forums, they do some crazy stuff with picoPSUs. I did some reading there when I was building an Atom server and remember people running some decent systems with picoPSUs. I think there was some way to get more 12v out of them.

I'd be careful though. Increasing amps in a 12v in a picoPSU increases heat and noise... something those OEM boards don't like very much.

I would be shocked if that system pulled more than 200w at full load. I think you'll be perfectly fine. CPU TPD is 65w, and the card is advertised at 20w "typical" load. That leaves you 115w for all the other peripherals and the motherboard. They won't pull that much.

After failing to POST at 120w (10A),
I finally found a 12v 15A Brick Adapter
With that 180w now she is running perfect (and fairly cool)
with a Slim BR tucked under as well. I stuck with the stock cooler as
this one seems to be super-silent. It's busy in there. Many, many hours of shaping perspex, but all worth it now !

Thank you to all for your help and replying, and especially to Dermen for guiding me to SPCR, and Weeman (SSD).