Server Purchase Advice Please....

Help.... I need some advice. I have 14 computers networked together for a temporary event for retail sales. Our cashiers run a point of sale software that sends alot of info back and forth from the server to verify price, id#, discount and description for every item. Our volume is like a grocery store during christmas. In other words 14 cashiers scanning items at the same time with high volume.

We keep having system temporary freezes for 10-15 seconds every 10 minutes or so....and want to purchase a new server to see if that helps. Our computers are networked together thru ethernet in a simple peer to peer environment (It is not an actual server but a desktop used as a server).

Question...Is it neccesasry to go with Quad over Duo given that it is only running 1 program or does it help with speed. Also...what is most important in this environment? Size of FSB cache? Memory over 4mb?

We keep wondering if we should switch to a true server with Windows Server 2008 running(as opposed to XP Pro). We do not need the internet if that matters...and all of the cashiers are together in one room....we just have to fix this freezing and slow processing issue!

I would be in debt to anyone who could give some great advice. Thanks!

Kim