Memory:
Take a glance at <A HREF="http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=842#842" target="_new">this link</A>, where I list a few sites that have done memory reviews. I use Mushkin High Performance Rev. 2. Corsair PC-133 CAS2 is supposed to be very good. Others recommend Crucial, etc. My personal preference is to go "name brand" rated at PC-133 CAS2. I just picked up some more Mushkin this week. I was tempted to get the Corsair but decided to stick with the brand I already have.
As to the best motherboard, the popular choices seem to be a toss-up between the Asus a7v and the Abit kt7. I bought the kt7 as it seems to be a little easier to work with. There is also an exhaustive KT7 FAQ at <A HREF="http://go.to/kt7faq" target="_new">http://go.to/kt7faq</A>. From what I've read, neither boards are without their own "issues."
Mike