I have a remote server (different country) with currently no physical access. Is there a way to do a remote clean install of Debian?
You didn't specify your server nor did you specify your server access method. You could access the server in one of these ways:
You also didn't specify if you can put in a CDROM or DVD or not. Assuming you can't, then the server has to support PXE and you need to setup a full PXE environment - including a TFTP server and a NFS server at minimum.
I would really see if a CDROM or DVD can be used; Debian doesn't have an autoinstall option that is as well documented and understood as Red Hat Kickstart or Solaris Jumpstart.
You can use preseeding (perhaps in combination with PXE and TFTP): http://wiki.debian.org/DebianInstaller/Preseed
If you just use preseeding you will still need to type a few commands at the boot prompt to start the preseeding. However with PXE and a TFTP server you can boot from a modified image that automatically loads the preseeding and requires no human intervention.
Though I have found that PXE is a hit and miss affair, with half of the systems which supposedly support PXE not working. So I decided to just use preseeding on its own and type a few commands at the boot prompt. If you have remote console access to the server then the only thing that needs to be done on location is to insert the boot medium.
Preseeding may a bit hard to get at first, but once you got a working script it's really quite nice.
I should warn about using PXE, TFTP and preseeding to completely automate a system install. It is possible to wipe and re-install an existing server that way simply by rebooting it. So you want to make sure PXE booting is turned off by default. On quite a number of systems it's actually turned on and the first in the list of boot devices.