Think you will find Largs very full, however here at Troon I guess there may be space depending on LOA. Better placed than most for travel from the south. 10mins from Prestwick and Ryanairs 1p deals or 40mins from Glasgow airport via the train.
15miles to Arran from Troon, a normal day sail for me, 3 hours out, a couple of pints ashore then 3 hours back........perfect. If you need more info PM me.