[KarmaKiller]

IMO, I really wouldn't waste the time nor money on those parts. Not trying to be rude or anything, but your buying a already outdated PC. Your not really gonna be happy with the performance gain (if any) you'll get.
But if nothing else, your really really really don't want the Power Supply. You NEVER want to skimp on the PSU's. If those go out, you can almost count on it taking other parts with it. And I'm sure you've heard the saying, "you get what you pay for" and that is SO true with Power Supplies.

Also, you have Laptop RAM picked out for RAM, not standard DDR2. So you'll wanna change that.
And for the price of that CPU, you can get a MUCH faster one for ~$5 more.
Newegg.com - Intel Celeron E1200 1.6GHz 512KB L2 Cache LGA 775 65W Dual-Core Processor - Processors - Desktops

If it were me, I'd save the money that you plan on spending above, and try to save up some more, so you can make this a worth while upgrade. You probably not gonna be happy with that system.
Hope I helped.