Ok so i edited my post after some quick thoughts:

Nah, we dont want to boat from Spain to Ireland, if that exists, or anywhere else, as we want it to feel like a Cycle HOME, not a tour, boat trip, then new tour. To make it a proper Cycle home.. it should be through England to Scotland, then the short ferry to Belfast, but we arent interested in cycling England, when we have never even cycled Ireland!! So i think.. we are sticking with Roscoff as our way of France, as thats a nice cheap ferry to the South of Ireland. So back to the original Q, how to get there...

Maybe we will do that other route when we come back to tour Europe, which i bet without a doubt we will be back to do in a few years....

On the internet side of things, i borrowed my friends laptop, started up a blog about this tour, and looked into charities, so soon, we will have a functional blog and charity raising means.