ok i have 1 of these.with my dvd burner in but u can either have a HDD or dvd drive in it.
{AC 5112} USB2 Only Ext. Storage 5.25" CD/HDD Enclosure
SVP Price: £14.98 / Euro 22.10 inc VAT.
http://www.blankdiscshop.co.uk/acatalog/drivecases.html
and then add this.
{HA 4116} 3.5" Samsung Spinpoint SP2014N OEM 200GB ATA/133 HDD/8MB Buffer (Stock Arriving Fri 26/08)
SVP Price: £58.59 / Euro 86.42 inc VAT.
http://www.blankdiscshop.co.uk/acatalog/hd.html
total price is £73.57.
iain