I've been in a small group for 17 years (we've ranged from 6 to 9 members) and we have done many a group project. Since each of you has selected two blocks, why don't you each select a fabric theme that you like (i.e. batiks, red/white & blue, 1930's repro, autumn, Christmas, juvenile brights, etc etc). Then draw up a master list so that each one of you makes 2 blocks each month, making one block for 2 of the other group members. On the list you will have the person's preferred fabric choice, which block to make and who to make for. For example:
Fabric Choices:
Ann - Batiks
Betty - Christmas
Carol - baby girl pastels
Diane - Autumn leaves
Evie - civil war repro's
Fran - red, white and blue
August: Log cabin block
Ann - makes for Betty and Carol
Betty - makes for Carol and Diane
Carol - makes for Diane and Evie
Diane - makes for Evie and Fran
Evie - makes for Fran and Ann
Fran - makes for Ann and Betty
September: Jacob's ladder block
Ann - makes for Carol and Diane
Betty - makes for Diane and Evie
Carol - makes for Evie and Fran
Diane - makes for Fran and Ann
Evie - makes for Ann and Betty
Fran - makes for Betty and Carol
etc. etc.
In 12 months, every one will have 24 blocks and will have made blocks for from their own stash for everyone in the group!