We just returned from a Viking Ocean British Isles Cruise. In Holyhead, Wales I definitely suggest Boutique Tours of Wales. The owner and guide John, has a passion and love of his Country and it shines through. He will take you places the big busses could only dream about and at a much fairer price.
In the Shetland Islands we booked "Shetland Minibus Tours". Grant is a pleasure, and we saw some fantastic scenery and visited some places that the Viking Tours could never reach.
Both are HIGHLY Recommended.