Steve when are you looking to cycle the route?
We hope to do it in July but we are not sure of our holiday dates. We will fly our bikes from Denmark to Stansted and hire a car/van one way to Penzance. We will stay in Penzance and ride out to Lands End and back to Penzance on the day we arrive. Our ride "proper" will start from Penzance the following morning.
Choosing the route is the most confusing aspect. There are hundreds of write ups of different routes. We will probably bring our camping gear, it is very lightweight. If the weather is good we will camp and if not we will B&B, hostel or hotel. We will only book the first night in Penzance and then see what happens. We can always wild camp.
To get back to Denmark we may hire a car from Thurso to Edinburgh and fly from Edinburgh to Hamburg and then train home, or car to Stansted and then home to Denmark.
We are looking for quiet roads and tracks where possible and maybe a little Island hopping up in Scotland. Sorting the route out will be a Winter nights job.