Hi there
I did exactly the same trip in 2002 when I had my good old Guzzi, sitting in pullman seats, and was not an awful thing; similar to the trips to Balear islands, which are usually 8h travel, you only use the seats for sleeping, occupying 2 or 3 sorrounding seats for your comfort, or just lay on the ground over your mattress and sleeping bag; one of the things I've learnt through many travels all around, specially by boat, is that you MUST bring with you an Ipod and/or earplugs, so no noise will bother you, nor will the deep rumble of the ship's engine. The rest of the time you spend it at the bar with drunk truck drivers telling stories, and in the morning you swim in the pool
No joke, at least back in 2002 they filled the pool with sea water and you really had waves and all. Back then you got in the boat around 10pm, and you drove out already on your bike around 4-5pm the day after. In 2002 this was the best way to get to Italy from Barcelona without having to drive 1000km through France. This was with Grimaldi lines.
I think now they have Barcelona-Rome also with Grimaldi Lines, I don't know if that suits you. Other than that, maybe Valencia-Rome?
Hope this is useful for you, post anything if you need further info
BTW, if you have to spend some time here before you embark, don't hesitate and call me, we can have some pints in a bar close to the ports!
