I would suggest you read over the section Overview of backup and recovery in SharePoint Server. This will provide you with the best guidance for out of the box backup and recovery solutions for Sharepoint.
It does not make a difference which server you perform the backup from, but you need to back up to a UNC share. Creating that UNC share on a separate disk on the SQL server will be the fastest possible backup you can perform (as
Backup-SPFarm or backing up from Central Admin will also perform a SQL database backup).
In general, for larger farms, the best bet is to use a SQL backup tool, either the native SQL backup capabilities or a 3rd party tool. You can then script the farm creation which will provide you with a consistent rebuild mechanism. Alternatively, you can create a configuration only backup via
Backup-SPFarm -ConfigurationOnly which will export the configuration of the Config database to the file system, which you can then restore to a new farm.
You do not need to backup IIS as that is taken care of by the SharePoint backup (full farm or configuration only).