Alfonso,

Thank you very much for the thoughtful and detailed reply.  I'm sorry that I wasn't clearer in my original post.  From c) your understanding/interpretation is spot-on.  Just to rephrase again:

1) seed --> voxel bivariate regression with 5-mm spheres and a priori non-directional hypotheses. 
2) marsbar --> write functional clusters from SPM.mat in SPM; extract eigenvariates from these clusters to explore directionality of group mean correlation (positive v inverse / strength).
3) enter new rois back into seed--> voxel bivariate correlation analysis; repeat step 2) for any significant target rois.  
4) repeat step 3) one more time.
5) calculate cohen's d for each group using group mean eigenvariate for each significant roi.
6) bivariate regression ROI-ROI analysis within-groups using previously determined ROIs.
7) where both directions (e.g., roi1 --> roi2, roi2 --> roi1) were significant, extract single-subject regression coefficients and run paired-sample t-tests on roi1 --> roi2 vs. roi --> roi2 to determine if there is any indication of effective connectivity.  
8) we also extracted denoised time series for each roi to explore visually.

Thanks again for the help!!!

-Patrick