Daniel, thank you for your kind answer!
I think using 3dcalc in order to extract values of each hemi of a cluster/roi (so I could enter them in ANOVA and test for independent_variable x hemisphere interaction) would do for me.
So, say you wanted to extract right-hemi value of a cluster, would something like this also work?:
"3dcalc -a cluster+tlrc -dicom -expr 'ispositive(x-0)' -prefix right"
The example above was one of very earlier posts, so I wasn't sure whether it was still valid..
Thanks!