In April with had the opportunity to rent a lovely cottage called Smugglers Den on the Island of Arran.  We walked a combination of coastal and hill walks during the week as well as exploring the Island generally and celebrating Fred's Birthday.  The coast path is not an easy, obvious holiday choice, because some is road walking and some bits need careful planning due to boulder hopping around the tide times, so we think your best plan is to combine the hills with the coast for the best of both worlds.