Oooh, geek time!
1) Wiki for CPU would be your first stop. In basic terms there a single, dual & quad core CPU's available these days, these compare (very roughly) as so - 3ghz Single = 1.5 ghz Dual etc....you see where that's going....If building a system to last another 5 years, you need to look at atleast a 2.5 ghz Dual core system. However, these CPU's come in many flavours and some are more user friendly than others.
2) The best fix for a slow system is a reinstall of the operating system following a full format. Failing that any system cleaner that clears the Temp folders, Internet files, registry etc aswell as defragging the registry is the best solution. Also a HDD dragging solution should be recommended, one that defrags via Name, Access etc, NOT windows defrag, it sucks. For a cleaner, I would suggest TuneUp 2007 or 2008 and for a defrag solution OO Defrag is the industry standard.
3) Yeah right, my old PC will run Crysis @ 30 FPS BUT at what settings? LOL, that's marketing for you. If you want a balanced answer for the PC offered, can you list it's specs?
What's your budget and let's see if we can build you a parts list.
