help needed: entry level / mid-end server

Hi all!
With two friends of mine we own a chat site w/15k visitors and 31k page imp. We need a new strong, but first of all: reliable (!!) server, and i need ur help guys.
We don't want to buy a brand server (such as ibm, hp etc.) because of the price - believe or not, we aren't millionaires
I thought a ServerWorks III LE based mainboard (intel stl2 or supermicro 370Dxx), 2 pIII 1Ghz and 512 ecc ram would be nice. Since this costs a smaller fortune for us, we'd like to know what we pay for..
My questions:
1. What u think of this config? What would u change?
2. Should we buy a board w/integrated Adaptec AIC7899 dual-channel SCSI controller & Intel® Pro/100+ (82559) NIC? Or better one without these, and buy a "separate" NIC & scsi controller (and if so, than which)?
3. IF a separate scsi, than should we pay the extra for a RAID-capable?

To help u help us, here are some infos:
- 15k users per day (unique ip), usually max. 2500 at once (record 3000)
- we'd hope to double our visitor and page impression number without buying a new (3rd) server again..
- strong sql (mySQL) use (<<user reg.)
- Unreal IRCD based chat server engine

Well fellows, that's it..
Thanks if u help me!! Write if u have further questions.

Thanks again and bye!


//endewel//