Ah, brilliant - thanks guys, there's plenty of useful info for me to waste away several hours of planning / daydreaming
The good thing about where I'm going is that there are no tides (well, only an inch or two at most) the weather stays the same for long periods of time, so if its flat and sunny it will be like that for weeks. Even when its not, the waves are big rolling swells, not that choppy mess we get in the Solent. I did some experimentation over Xmass in some large rollers, just surfing on the top, or scooting along in the trough. They were large and predictable.
Unlike the Solent its also pretty simple for Navigation. But I will take a backup compass / paper map / GPS etc. Its quite mountainous so you can just point the boat at the next headland as you can see it miles away. If the weather does start to change I can zip back to my start/end point in double quick time. I'm also taking two 20L jerry cans of fuel just in case. Fuel is only at the main marinas and they are far apart.
I've got a decent range at cruising speed, trouble is when its flat and sunny its so easy to think cruising is 45knotts
I'm also planning on a few nights where I will bivy on the beach in some of the isolated coves along the way. So a line and bait as well as something to start a fire will be added to the list of stuff to take.