8 weeks to wedding - matrons of honor fighting over dresses

Dear ESB:

A little background.  Several weeks ago one of my oldest and dearest friends took her own life.  I have been dealing with the grief as well as the memory of having been the person who went to her house to be with her mother while the coroner came.  My fiance has been a constant source of support.

In light of the tragedy as well as having lost another good friend in the past year, my fiance looked at me and said, "Life is too short to spend a year planning the the perfect party.  I want to marry you right away." We quickly found a venue available eight weeks from now, cleared the date with our family and closest friends and made some fast decisions. All has been going well until I spoke with my sister and best friend, both of whom I hoped would stand up with me, about what they should wear.

I thought I was being laid back by telling them there is no time to worry about traditional bridesmaid attire.  I let them know that what is important to me is that they are there by my side, and feel comfortable and beautiful in whatever they select. Since both ladies are infinitely more fashionable than I am, I didn't think it was my place to tell them what to wear.  They both are familiar with the venue, know what my dress looks like and attend formal events on a regular basis.  Wrongly. I assumed they would be thrilled for the chance to either shop for something new and fabulous without any restrictions, or wear something beautiful and appropriate that they already own. I offered to go shopping with them either as a group or each individually if they would like. `

Since I discussed this with them there has been nothing but drama.  Both are very concerned that the other is going to select something that will be "better or more sexy" than their selection.  I tried providing guidelines, based on their input, I even suggested that both just wear black to keep it simple. This escalated to more infighting and no one willing to even discuss what they might wear because they want to wait until the other one selects something.  I finally asked if it would be easier if I just picked a dress off the rack for both of them.  This was met by looks of horror and the exclamation of one with "You know Matron 1 is a completely different body type than me." and "That just won't work. I am not a cookie-cutter person." from the other.

How do I handle this? Do I give them each other's phone numbers and tell them to hash it out? I was in both of their weddings and wore the dresses they selected for their bridesmaids without complaint.  There is so much bad blood about something so trivial that I fear that the real reason My fiance and I are getting married is being eclipsed by this diva war.

Any advice would be very welcome.

Thank you