Heres a nice case if you really want to go mad,
http://www.komplett.ie/k/ki.asp?sku=...&view=detailed
But if not I would recommend a coolermaster. One of the ones where both sides
of the case are on hinges so they can be opened with ease. ie. no undoing
screws or taking parts off of the case.
I think you should stick with amd also. maybe upgrade to a 3500 or 4000 amd64
athlon or something like that.