i did a search for NES PC on here, but didnt turn up any results relating to what i want to do....however i'm sure someone has already asked this question before. i actually may have myself a few years ago, but ive forgotten

so here goes...
there are tons of people out there doing NES PC's...i googled....but most of those people want to use the NES PC for all kinds of extra crap. i JUST want it to run NES emulation/roms. so no complex video, or nintendo 64 cpu power requirements or anything like that, just simple nes emu. with that in mind, i want to build this with as little cost as i can. i already have most of the hardware, cept for the mini-itx board ill need to put in the NES.
so first of all, i have a few questions. i went to newegg and found this board
http://www.newegg.com/Product/Product.aspx?Item=N82E16813185103 . its $25 after mail in rebate, and its got the cpu already built into the board (800mhz). i went to this site
http://www.instructables.com/id/Build-a-Nintendo-NES-PC/ and looked at everything this guy did...however he has a whole lot of other emu's that he's putting on there, so im hoping i can save some $$ by building a very low horsepower pc. here's what ive got so far without having to spend money:
1. NES w/ 2 controllers (hoping to use those...whether i mod or buy usb converted NES pads, i want to use the NES controllers)
2. laptop hard drive
3. laptop CD Rom drive
4. extra case fans if necessary
what i think ill need:
1. mini-itx mobo with cpu - $30
2. IDE converter to plug drive into mobo - $10-15
3. RAM - i need DDR 266 but i think the old laptop i have should have that, but if not - $20 or less
4. external power brick - $??
so here are my questions:
1. im assuming my 800mhz cpu/mobo is plenty for nes emulation right?
2. OS - can i just use dos or will i run into driver issues with the controllers and such?
3. i can probably find a tutorial on how to convert existing NES pads to usb, but ive never soldered anything in my life soooo....yeah....should i just buy some converted NES usb pads??
4. any other suggestions before i embark on this venture??
any help would be greatly appreciated.
