Photoshop CS4 hardware question

I'm planning on building a PC dedicated to Photoshop CS4 and the latest
Lightroom. I'm told that for a workflow that does not depend on
continuous coffee breaks to allow the machine to crunch image data, a
very powerful machine is requisite. I'm told that a 64 bit system with
as much RAM as one can afford is what makes it possible to fiddle with
multiple layers and do extensive comparison of effects, etc. I do know
that a timely response from the machine is necessary to keep the
creative juices from stagnating (shriveling on the vine, so to speak),
so those requirements make some sense to me.

OTOH, I'm told that CS4 runs just fine on much less powerful systems,
that a 32 bit system is more than enough to handle anything that one
might want to do with Photoshop. As I don't have access to the code of
Photoshop, I can't evaluate it's ability to shine on such systems, but
I'm not that sanguine about coding miracles from Adobe in any case.

Some of these issues are addressed in an excerpt from "Real World
Adobe Photoshop CS4 for Photographers" by Chavez and Blatner. Check out:
http://www.peachpit.com/articles/pri...aspx?p=1247538
A local acquaintance has touted very expensive Apple systems, while
others talk about laptops, saying that they are more than good enough.

I really don't want to have to hock the house for a genuinely useful
system, but if that is what it takes... nah, the house is safe, but
other money pits that yawn nearby are surely not. On their behalf,
therefore, a question in this regard is appropriate. So...

What is the experience of CS4 users in these regards? What sort of
system works best? What sort of system works well enough that using it
is not an onerous task? What am I looking at here? And what is it that
I don't understand; what question do I need to ask that I'm not asking?

Another question: What is the experience with good LCD monitors? What
is a "good" LCD monitor and why is it "good"? I've got a couple of good
CRT monitors, but don't know that they can be replaced. The guy that
talks up the Apple system claims to have one, but he says that it's very
expensive (presumably it's an Apple monitor). What is the reality here?
Anyone know?

Thanks for reading. All useful responses will be duly appreciated.

Longfellow