Hi i am after a second computer but i will only be able to use something less than 16" high as it will be placed under a shelf ...I have seen this dell http://www.dell.com/downloads/us/products/precn/ws450_spec.pdf
Whats peoples opinions on them ?
Been offered one at £120+vat reconditioned or should i just buy the parts and build one ?

What can I say, it's ok. It's nothing special, it's not brilliant, but it will be well built and tested and come with a complete system warranty. If I wanted a new DHCP server I'd consider using one. Price is fair.