Lots of advice needed on new HA server setup

["Paul Gale" <groups@xxxxxxxxxxxxxxxx>]

I'm looking for lots of views and opinions on the following please...

Another set of advice and recommendations needed for my new HA and home
office server infrastructure.

This is my current HA and business server PC setup:

1. Main Server (W2K3) running Exchange, IIS, DHCP etc + LOTS of HA Apps
2. Geovision CCTV PC (XP)
3. Asterisk @ Home Linux PC
4. Bonded ADSL router (Linux)

The main server is suffering from 90-100% CPU utilisation for a high
percentage of the time, so I want to split it out to two boxes, one the
Exchange and traditional server bits and one the HA bits. I also need to
try and quieten it down as it uses noisy fans and especially disks. It's
currently a dual P3 1 Ghz 1GB ram machine. Also want to get RAID5 array in
there with hot swap capability etc.

This is what I'm thinking:

1. Main Server - W2K3 R2 Standard server
Running:
Exchange Server 2003 Standard (only 2 accounts but lots of old email)
RAID5 file server array (1TB?)
DHCP, DNS, WINS etc
IIS
FTP
POP2Exchange

2. HA Server - Possibly running W2K3 R2 Standard server?
Running:
Telcanto MP3 Server
WinAmp multi zones
HomeSeer 2
HomeSeer Speaker inc VR?
xAP Switchboard, Ping, Hub, Tel, Weather, Speech
Main Lobby Server
NeoSpeech Voices
Anything else that comes along

3. Geovision CCTV PC - XP or W2K3 Server?
1240-8 Geovision card
Geovision software only
P4 2.4GHz min
1 Gb RAM
400 Gb HDD

4. Asterisk Server
Existing Dell SC420 box ported to rack mount case???
CentOS Linux
Asterisk @ Home

5. Bonded ADSL Max Router
Proprietary Linux build
3 x ADSL PCI cards

So what do you think?

My questions are:

1) What OS's would you use on the HA Server and Geovision PC and why?
2) What hardware spec would you use on the main server and HA server?
3) Are there any rack cases that:
a) look good - aesthetics will be important
b) are quiet and allow good airflow
c) don't cost a fortune
4) What redundancy would you build in? I have a large UPS but would you put
in redundant PSU's etc? Anything else?
5) Heat output is an issue, so need to keep it cool as poss - what
processors and disks would you use?

Anything else?

Many thanks,


Paul.