That Bride asked me to pick out a few ties for That Groom and his cohorts. She warned me that he's a little conservative, but I think a classic Hermes tie would be just the thing with his two-button black suit.
(Jenna, if he balks, tell him to read this by GQ's Style Guy.)
This one would perfectly complement the black dresses/gold belts/black & gold shoes the bridesmaids are wearing. (It's listed here on ebay for 38 more hours. Currently at $24.99!)
This one brings in the hunter green, and the greek statues are a nice reflection of your old world travel theme. (Listed here on ebay, for $109.99.)
Then I'd add Classic Solid Ties from Brooks Brothers in black and gold for those groomsmen (on sale for $69.50/buy one get the second half off).
I like letting the groomsmen's ties be assorted, but in the same color scheme as the maids. If you let in too much color here it could start to feel like a hodgepodge.