qcamel - info on Port St Mary:
http://www.iomyc.com/Default.aspx
When are you coming over?
A couple of Pubs do rooms - nothing too fancy though:
The Bay View is up a short hill overlooking the Harbour. Can be noisy at weekends with live music.
The Station is a bit further, around 5-10 mins walk and seems a bit quieter.
The Pick of the lot is the Albert Hotel - right on the harbour, great beer, food and atmosphere - plus they do rooms. 01624 832118 - no connection, just my favourite local.
Member Whitingiom may havesome other suggestions?