Labour required for porting Quake to a hobby OS.

Well let's see what I first think about what should be in my OS.
Compilers/Assemblers
Text Editor
Scripting Language
Other Puke.
Well on OSdev I saw a guy called sortie port Quake 1 to his OS. And seeing
that I got damn jealous. It could be considered as an act of foolishness but
I soon got to know it isn't impossible.
And I'm in no hurry to port Quake to a "Mikeos" clone.
I consider the following as very important :
C Library
Memory Segmentation
Relocatable Executables (MZ Format)
Mouse Support (Does Quake implement its own mouse driver)
What else would be required?
I am pretty aware that after the port my OS would not be a Mikeos. And I am studying the source + Intel Manuals.
Plus which game would you think would be easiest to port to a Real Mode OS.?
Any more suggestions?