Backend Server & Security Admin - Plesk - Apache - Media Temple

We have a MediaTemple (dv) Dedicated-Virtual 4.0 server. It is running plesk 11. Looking for professional security/anti-invasion/ colleague. We also want this person to help us created a backup/restore process. I have had some recent issues with security, had someone broke into CMS and put in some php files..maybe they entered FTP...I changed admin password/ftp passwords and deleted the files but I cannot run a business like this... I have to connect with one or two expert server side admins who can help me, mitigate these future risks by being proactive about security/firewalls etc.... We are only a startup and I am looking for consideration on price but as we grow into a larger company, I will be able to provide more consistent work. We will succeed and I just need to know that our websites and information are being fully protected. We would most likely start with a 2-3 month contract. After each month we would pay you for the month. Please also let us know about your recommended pricing model. Thank you for applying/contacting. Chris