T-Shirt Quilt IV

I have the third block done! so now I have three approximately 11' square each block that I will assemble into a throw. I have a fourth square to make to round out the grouping for the throw. I'm using extra pieces that I was given that aren't the same appliqued t-shirts but are from the same sorority to make the fourth block. I'm having trouble deciding which fabrics to do the borders in.