Yes both Boeing and Airbus offer installation and activation on customer request on most new equipment types.
Yes Rockwell Collins ARINC is certified to complete an HFDL installation.
It can be quite extensive depending on the existing levels of hardware functionality, software, certification and aircraft manufacturer. New common forward fit use the existing Rockwell Collins ARINC HFDL network, if installed it just needs to be switched on and incorporated into pilot procedures.
It is dependant of the existing levels of current hardware, software and provisioning.