Building new system, asking for input (& have some questions)

I'm building a new system (still looking at the parts) & am running into a
few questions.

First off, my motherboard, I'm debating on the Gigabyte GA-K8NS-939 vs. the
939-Ultra (NewEgg shows $27 difference). The Ultra has some features that
while I may not initially use, they may come in handy later. Other than
that, I'm looking at the regular GA-K8NS-939 board. Also the board specs say
it only supports the 130nm but others say they use a 90nm on it. Is this
just a overlook/forgot to update the info or does the board really only
support 130nm? (& what is the real difference?)

My other biggest question on the motherboard is the heatsink mounting. I've
read that the board uses plastic screws which would be a problem, but are
they meaning the board to case mounting screws? If so then can't I just use
some others I have as a replacement? I'm looking at the "ThermalTake
ComboCool DIY Tower112" (NewEgg part#N8cE16835106044) which is a 60x60x145mm
size & looks like it mounts THROUGH the board to the case (because of it's
weight).

Next, I'm considering either Kingston or Corsair memory, 512MBx2 dual
channel memory at 400MHz. My problem is finding compatibility of them.
Kingston's website lists the Gigabyte boards as GA-K8NSXP-939, which I'm
sure is just a naming problem/typo on their part considering they didn't
have anything else closely resembling this board. But what is the
difference with Corsair's XMS memory vs. regular RAM?

Also in graphics cards, I'm debating on either an ATI All-in-Wonder Radeon
9800Pro or a non-AIW card so I can have 256MB instead of only 128, & get the
TV-Wonder2 or something like that for the video capture & TV abilities
(which that device would be portable being USB2).

Any good recommendations on power supplies? I'm thinking of a 400W.

Any input is very helpful as I'm building this in another week or two.

--

There are 10 types of people in this world...
....those who understand binary & those who don't.