The most technically amazing system in the world is useless if people in question don't want to spend the extra effort to learn how to use it.
It sounds to me like the best system is SVN as the core repository, then people can use git if they want, and sync it to SVN. Miller currently does this with Git->CVS.
I still don't think that git is all that hard to use once you understand the distributed paradigm, but in any case I think this would be a perfectly safe decision.
One thing I've learned more recently about version control is that it's not actually _all_ that hard to switch from one SCM to another, since there are usually conversion scripts in every direction imaginable. (Except, for som reason, Anything->CVS, heheh..), so I think it's worth trying out at least.
Just keep in mind that converting from subversion to something else in the future will be easiest if you stick to the standard /trunk/tag/branch structure. One of the features of svn that I just love is how there are no "modules", but instead every subfolder is like its own repository. However, this can also allow you to create structures that are difficult for other SCM systems to interpret when converting (since there is technically no difference between a branch and a tag), so sticking to /tags and /branches at the root level may be safest option.
Steve