SQL Navision installation on a Compaq Proliant 350

Hi All, I’m wondering if anyone has done a configuration of a SQL server on a RAID5 and RAID1 configuration. Because of the nature of the server currently at the client site, I would like to keep the RAID5 for the OS and pagefile, and purchase extra HDDs to progress further with a RAID1 configuration whereby there will be an extra logical drive / and/or two for the database and the transactional logs. Does anyone see any flaws in this concept? If so I would like to hear and discuss. Very much appreciate any feedback. Thanks first, Yoong Luu