Here is FI's suit from Men's Warehouse (except without a tie):
And the GMs attire:
I freakin' love the shirts! Our dads are wearing the same shirts in a different color. The shirts are from Beach Wedding Attire: Drawstring Linen Pants, Cotton & Linen Shirts, Shorts for Men & Women - Island Importer, the shoes are from AE and the pants are from ON.