New server setup and RAID recommendation

[serge]

I have a database that is around 2 to 4 GB.
If I were to estimate some numbers like 4x growth or
even 10x, the database size could reach 40GB.
The new server will be running SQL Server 2005.

I am not sure which configuration option to take.
I've gathered some information from different places:

Configuration #1:
OS - Raid1 2x36GB
Logs - Raid1 2x36GB
Data - Raid 5 4x73GB
Configuration #2:
OS - Raid1 2x36GB
Logs - Raid5 (not sure how many drives)
Data - Raid5 (not sure how many drives)
Now if I am using a separate RAID array disks
for the database's transaction log, should I also put the
TempDB in this RAID also?

Here's the configuration I am thinking of right now.
Please give me your comments:

OS - Raid1 2x36GB
Logs & TempDB - Raid5 3x36GB = 2x36GB usable space
Data - Raid5 3x73GB = 2x73GB usable space

If you have other configurations you recommend please let
me know.
Thank you

[LLik]

For the install and forget about I want protection and speed at a low
cost use RAID 5 for everything.

Now if you want the best performance and protect for the type of work
being done use the follow.

For the system files and executables, reading binaries doesn't really
put much overhead on the servers, so it is not a major concern. Any
RAID level could be used.

For data files, RAID 1 is preferable because it gives the best tradeoff
between performance, protection and cost. Because it is 100 percent
redundant, it both protects the data and the availability of your
system. Availability is the reason that you for using RAID with a
database, and even the loss of a small internal database can bring down
the database server. In this case, you will not lose any data but the
users will have to live without your system. If performance and
security are your major factors then RAID 10 should be used. No matter
what RAID level is used each RAID array should have as many physical
disks in the array as the controller will support. This allows reads
and writes to be performed simultaneously on each physical drive in the
array, significantly boosting disk I/O.

Log files, by their nature, are mostly written to, which means that
often RAID 1 is your best choice for performance. As with the
database files if performance and security are your major issues RAID
10 should be used.