right then going by philips LS1400, took me a while to find out something. what you might be looking for is a mini ITX motherboard, or a m-ITX m/board
i'll put in the link to show you which one. im guessing the pc you have there is quite compact and similar in size to an acer X1700
there are some retailers that do trade in mini-ITX components, but not a lot of them, try googling mini-ITX and see if you come to any results for retailers
the one i found is
http://www.mini-itx.com/store
and another is
http://www.itx-wareshouse.co.uk
http://upload.wikimedia.org/wikipedi...Comparison.jpg