That should work. As noted you will not need the bracket. It will fit. Can't find too much detail but it is the type you would want. Yes.

There is also a 256MB version here

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I would suggest sticking with the 128MB model as I am unsure if your 200W Power Supply would want to be pushed much further.

Looks like a winner then. The salesman said that XFX are number 1 for nvidia graphics, maybe it wasn't just a spiel.

Should be a good upgrade!