use the brick with a dc/dc atx psu.
you can find some 200w versions here:http://www.mini-box.com/s.nl/c.ACCT1272 ... gory.13/.f
i googled a bit but couldnt find anything higher than 200w. they do say they have 95% effeciency though.
could you hook the brick up to one of these, plug it into a micro atx motherboard, and run some tests?
some things i'd like to know. exactly how much would direct charge for its PSU brick, cause it didnt state that on the website. also what sort of effeciency does it have. does it even output a full 220w? and finally how well would it work to use it in conjunction with a dc/dc atx psu on a micro atx motherboard.
They'll need to have the same connectors, and the rated input of the DC-DC board will have to match the rated output of the brick.
About efficiency, I'd think maybe 85%-ish, about 80% overall including th DC-DC board. A member on here tested the efficiency of a Lex 120w brick and DC-DC board, and I think it was high 70% to low 80%. I'm sure it varies from part to part, though. I think he was also running off 230VAC, which is slightly more efficient in PSUs than 115VAC.
For a while I used a 120w Lex kit in my Turion64 computer. It worked pretty well, but I noticed a few of the inductors (or maybe they were transformers?) got pretty warm without any airflow over them, and this was with a very small load, probably 50w. I dunno what the heat ratings on these things are. They're just copper wire wrapped around a piece of iron, so I'm sure it can handle a good amount of heat. Still kind of bugged me, though. If you plan to run 150w+ through a DC-DC board, you'd probably want to make sure at least some airflow was moving over it.
And just to play devil's advocate, are you sure that adapter doesn't have a small fan in it? I've heard of some that do. It probably wouldn't turn on at low loads, but if it ever did turn on I'm sure it'd be annoying.