Hi,

I'm a little bit confused about what the exact commands and names fo the files are-- rather than retyping, in which things (spelling, options, etc.) can change, copying&pasting the exact commands would be preferred.

If you just want to view the *.gii surface with the *.niml.tract file simultaneously, that can be done using a single command with SUMA:
$ suma -i anat.gii -tract L_pL_000.niml.tract

and then you hit the '.' (=period/fullstop) key to toggle the surface on/off (while the mouse cursor is over the SUMA display window).

The '-i SURFACE_FILE' loads a surface and the '-tract TRACT_FILE' loads a tract file. You can open the object viewer and color the surface variously as you wish. Some tract+surface examples are given here:
[afni.nimh.nih.gov]
(scrolling down that page a bit, there are some SUMA+DriveSuma examples, as well.

Does that work for you?

--pt