Speaking of food if the reception (ceilidh) if you are planning a buffet try to source Scottish (mutton) pies ans Scotch pancakes (also called drop scones). If there is someone that is adept at cooking there are ample recipes and they are not complicated. As for the cutting of the cake don't go overboard but look for a claymore or a basket hilt sword. I am sure there must be hire ones available at costume hire or wedding attire hire such as your own? For gifts to the best man and the others of the party retinue if it is Irish themed, pens shaped as shillelaghwould look nice.