Linux SysAdmin & hosted asterisk VoIP gateway etc

I have a hosted VPS that I need some routine security and sys admin tasks done. It is a low volume VPS - only a couple of part time users and a 6 domains mainly used for email. I have one important CRM application - 2 users. Based on SugarCRM (PHP+MySQL) other than that a few small & simple joomla sites and email both POP and IMAP. This VPS may be small and low volume but all domains and services are important to me and I do not have the time required to setup and manage this server or the apps etc. I will explain further, provide all details (inc root access) with the winning bidder. The task I need completed are as follows: 1) I want the sys admin to do an initial site check of all services and fix or enhance security as required. 2) Fix some IMAP mail issues on a CRM application (similar to SugarCRM) 3) Implement a VoIP gateway and VPN service - I need the SIP link to my server inside a VPN - this is a private (NON commercial service - simple and small) 4) Provide ongoing support - say 2 hours per week for 3 months maybe hours more by agreement. I want to agree a fixed fee per week for two hours of agreed regular sysadmin and minor work. Plus an hourly rate for additional work. 5) I will pay through freelancer.com Please do not reply unless you have a good rating AND have experience of Asterisk or other Open source VoIP servers, VPN, Linux Sys Admin and SugarCRM or vTiger. Please provide bid prices in 3 steps: Initial work - (Task 1, 2 +3 above) Weekly Admin - (task 4 above) Hourly rate for additional work (task 4 above)