Don't use time machine on your server, it doesn't backup everything you need and is very inconvenient and time consuming if you ever have to recover from a failure.
The first line of defense is a clone.
Carbon Copy Cloner or Super Duper to an external drive
If you entire server failed, you can use the clone on another workstation and restore service with very little downtime,
Cloning is an exact duplicate, its not going to protect you from a file deletion, or even a corrupt OS that existed when the clone was run - so consider cloning as the most important layer of a full backup strategy.
Add to this some form of archival backup to allow recover of deleted files or restoration of an earlier version of files/directories. You could use a cloud service for this so that you also add offsite archiving of important data.
crashplan works well for many, it does have some cpu/ram overhead because it runs inside a java vm.
The offsite backup is only for you 'data' and not the OS/Applications.
If you want offsite backup of the entire OS/Apps/Data, a simple method is to clone to 2 or 3 external drives and rotate them offsite.
hope that helps