I'm coming very late to the party!
I had a heck of a time finding nice wedding attire for my boys last year when BIL got married. I ended up with black dress pants from goodwill, white button down shirts and home-made vests & ties.
I found vests that fit at goodwill to use for size-specific patterns and a lined vest pattern
from an internet search. The outside of the vests was brocade (black wwith subtle gold & silver dragons) and the lining was 'butter' one of the wedding colors. I made bow-ties out of the liner & sewed them onto the shirts.
My boys looked awesome. They matched each other and coordinated with the wedding colors. Since DH was in the wedding and I coordinated, too the whole family looked awesome