Choice of Right Hardware(DESKTOP)

I need to buy a desktops for a small business which is specialising in converting analog VHS tapes into DVDs. They are actually going to be doing a lot of burning of DVD’s. A solid DVD drive that can handle all the formats is a must. These files will be transferred over the internet to their various service centers. Please advise on a stable system that can take this abuse. Also some of these desktops will be sent to places with little technical support so hardy system will better serve the purpose. I am looking currently at the Sony VIAO RZ54G.
Should I consider building them from the scratch and if so what are the most stable components.