Simply no for the first one.
Setting up a gameserver is fairly complex.
First thing you should worry about internet connection, you can`t have a great gameserver on a standard residential internet connection. First thing to look at is static IP.
Second thing is what games, and what type of performance do you wantÉ Modern games will require better hardware than what you have selected. But for a basic game like CS, I can run a 66 tick 500 (set, not real) FPS server on a P4 2.53, and thats cutting it fairly close. 100 tick is not doable, even at 66 tick the latency gets a bit high.
Ram depends on what you want to run, a stripped down server running a single instance of Steam Server (CS:S, HL2, etc) or something like COD2 will run on 512 ram.
Third, hard drive speeds matters ALOT for loading times. However a modern 7200 RPM drive with 16 meg of cache will suffice.
A cheap Core2Duo with 2GB of ram and a new seagate 7200.11 drive will run circles around any used server under 250, it`s the route i`d recommend unless you need ultra-high reliability.
I`ve ran quite a few gameservers, so feel free to give me a shout on AIM or MSN if you need anymore help.
EDIT: Running linux instead of windows can also really help on gameservers
Using CentOS or Ubuntu for a game server is fairly easy.