Here's the short list of possibilities (FYI, HAL is generally more single friendly)
Please check VTG for routes.
Days;Dates;Start/End;Line;Ship;Approx pp w/ double occ
7;22-Apr-08;Rome (Civitavecchia), Italy;HAL;Noordam;1,349
10;29-Apr-08;Rome (Civitavecchia), Italy;HAL;Noordam;1,699
10;9-May-08;Rome (Civitavecchia), Italy;HAL;Noordam;1,699
12;21-May-08;Rome (Civitavecchia), Italy;Royal;Legend of the Seas;1,749
12;2-May-08;Athens (Piraeus), Greece;HAL;Rotterdam;2,199
12;14-May-08;Athens (Piraeus), Greece;HAL;Rotterdam;2,199
BTW, had dinner with a fellow cruiser and author of a new book "Spontaneous Tourism" this week exchanging stories of our travels and got some tips on hitting Europe. I may do a 5 day scouting trip from Rome to Istanbul to Cairo to check logistics.
At this point I have folks expressing interest, but no committments. There are a bunch of us solos and singles who would like to do Europe, but we are as hard to get together in one place as a herd of cats.