Howdy-
Well, just note that we have done something similar with FreeSurfer on template data, and have packages you can download. In this case, you could run:
curl -O https://afni.nimh.nih.gov/pub/dist/tgz/suma_MNI152_2009.tgz
... or browse this webpage for suma_NAME of template you want.
One benefit of going this route is that, as actually came up in another recent thread here, one should probably reattach the proper template space designation within the headers. We have done this now/recently, as part of the question pointed out helpfully in that linked post.
Yes, volumetric data can be projected onto surfaces. This one of the ways that SUMA and AFNI work together: 3dVol2Surf projects volume -> surface, and 3dSurf2Vol projects surface -> volume.
The help file for 3dVol2Surf has some starter examples of what you want. Maybe it is best to try using that and see if that accomplishes what you want?
I will also note that we have some AFNI Academy videos on SUMA functionality, with the general overview here and then additional advanced topics here.
--pt