Hi Andrew
I may be wrong, but I think you might find that many owners have already got summer holiday bookings so you might find it difficult to get a long term let for 6 months.
I could do 2 moths for you but that is all!
Try Maggie and Dennis at Roda FM - www.rodafm.com - they have a number of properties that they manage so may be able to help.
I'll also send you a PM.