Something along these lines: http://www.newegg.com/Product/ComboBundleDetails.aspx?ItemList=Combo.770956&cm_sp=DIY_PC_Combos-_-770956-_-Combo,
would be much better than the Alienware system you are looking at. Add an aftermarket CPU cooler ($30-$60) and you would easily be able to overclock CPU to around 4.5Ghz. Than use the rest of your budget for a monitor. This setup would also let you SLI in future if you desired.
This is a pretty nice package deal. The only drawback is no included operating system, but I'm a student and get get a copy of windows 7 premium for $65.
Thanks for the feedback, this is probably what I will go with.