As far as memory,you may want to check out here:
http://memman.com/
On Memmans page there's a link under the infineon 133 mhz to a review on memory well worth reading,as it gives one, good insight on availabl memory and what seems to be working well.
There may be two devices that can give you problems the GeForce(most problems have been resolved,but can still prove to be a pain!)
The other is the Aureal soundcard.
Aureal is on the virge of chapter 11,so future support may be dubious.
I had the misfortune of attempting to install 2 Turtle Beach(retail)MontegoII sound cards using the Aureal chipset.Both cards were DOA.
Windows didn't find them,tried every trick in the book,attempted to contact tech support,no go.Installed drivers,no go.
No uninstall feature for drivers and had to go through registry and system to get rid of them.
Got a SoundBlaster Live Value and although it's on a customer's computer,find myself constantly playing with it.Ultra cool!
Easy to install.Excellent quality,excellent support,affordable.
Just make sure it's assigned to irq5,and all is well.