not for me but it might be a good idea this time of year if you put your bike on a train and got off some wear warm, know if I could ride in the warm I would not mind paying £300 ish, just a thought.
Mav, I was about to reply to your first post before it was savaged by rubberlips. My suggestion was to be a full itinerary, but you seem to have that one covered. I was once considering an escape to Almeria but gave up cos I got lost in the "how do I get there" stage, also couldn't work out a close enough cost estimate with having to plan all aspects through different agents and was browsing booking forms by trial and error.
The one-stop-shop would've been my choice, someone to whom I could give prefered dates and let them do the rest, and someone who'd ask me the right questions to work out what's best for me. I'd've liked boat/hotel bookings to be made, routes planned by someone who knows best, fuel cost estimates, route maps and ETA's. Maybe also some advice on local road rules and etiquette too.
Hope it all works out for you dude, cos I might need you one day!