URGENT Please read Main ata connector dead -

Hi it's me again and i need to to make a decision, re: main ata has finally bit the dust.
The problem started as intermitant over a 2 month preriod, the 2 drives on the main ata started with the master or slave not showing up on the desktop.
Now the ata slot is dead, tried any and all sugesstions in this forum.

Had the Geek Squad here yesterday, they charge $159 just to diognose the problem, $100 more to fix it!

I was told that it could a sign of the mother board could be failing, i did not want to hear that

I cannot afford that and still buy a 250 gig drive

I gave decided not to spend the money to diagnose the problem.

I was going to buy a WD 250 gig extenal Firewire drive for $159.

Now i have heard i could install a SATA drive, sounds like the way to go,
I need help on exactly what a SATA drive is, what do i need to do this, does it need to be connected to a FireWire port, or a pci card.

I weighed out the options, and forget the main ata, and just get a new SATA drive

I need to know what i should do
a.) Buy the WD external FireWire or
b.) Go the Sata route
Option b seems like the better way to go, but i need more info from all you experts,

Need to make a desision by the end of the week.

sknoxx