first off the amount of gene manipulation you would have to do to make a possibly brainless clone with viable stem cells is faaaaaaaaaaaaar from aaccomplishable right now
Not brainless, brain dead.
And you don't need a full clone for stem cells; a fetus does the job quite nicely. If you take a full clone, it's already formed and it's useless unless you plan on taking the organs. (Or a full-body transplant, but now
that is far from our technological reach.)