Raid 1 or 5 for Colocation server with 5 wordpress sites, 1 CRM and 1 mail server?

Raid 1 or 5 for Colocation server with 5 wordpress sites, 1 CRM and 1 mail
server?

I want to buil colocation server with :
5 Wordpress sites with 50 view at a time (5*50 = 250)
1 CRM ASP.NET site with 50 view at a time
1 mailserver Kerio connect or MDaemon wiht 120 user
My model :
Server A - ESXi 5.1
Mysql1 on CentOS 6.4
SQL1 on Win2k8
IIS1 on Win2k8
Apache1 on CentOS 6.4
MDaemon1 on Win2k8
Server B - ESXi 5.1
Mysql2 on CentOS 6.4 (cluster Mysql1)
SQL2 on Win2k8 (cluster SQL1)
IIS2 on Win2k8 (cluster IIS1)
Apache2 on CentOS 6.4 (cluster Apache1)
MDaemon2 on Win2k8 (backup for Mdaemon1)
Please advise me should use :
2 HDD SAS 15k with Raid 1
3 HDD SATA 10k with Raid 5
Thanks