Looking for a cheap upgrade (RAID)

I have a server on a standard pc right now.
PIII 700, 1Gig ram (SD), 40 Gig IDE, RedHat 8.0, PostgreSQL 7.3.1

The database has 3 tables that just broke 10 million tuples (yeah, i think
im entering in to the world of real databases ;-)
Its primarly bulk (copy) inserts and queries, rarely an update.

I am looking at moving this to a P4 2.4G, 2 Gig Ram(DDR), RedHat 8,
PostgreSQL 7.3.latest

My primary reason for posting this is to help filter through the noise, and
get me pointed in the right direction.

I realize that Im a raid on linux newbie so any suggestions are appreciated.
Im thinking I want to put this on an IDE Raid array, probably 0+1. IDE seems
to be cheap and effective these days.
What ive been able to glean from other postings is that I should have 3
drives, 2 for the database w/ striping and another for the WAL.
Am I way off base here?
I would also appreciate raid hardware suggestions (brands, etc)
And as always im not afraid to RTFM if someone can point me to the FM :-)

Cost seems to be quite a high priority, I'm getting pretty good at making
something out of nothing for everyone :)

TIA for any suggestions.
Chad