Your number one aim, should be to be able to write, save and compile your OS, as soon as possible, on your own OS.
If not then as C programmer's, you might as well use linux.
How else are you to know how good or bad your OS is, unless you use it, do you not think linux developers could not of much easier used windows stuff, than used very basic tool, on what was then a very bear bone linux.
Developers who do not, do this, are nothing more then OS dev equivalent of Script kiddies

Note: This does not mean reinvent the wheel, but you should at least try to port them to your OS.
Oh, but i forgot, that may be a little difficult for a C complier like GCC compeared to a assembler like fasm.