I was recently licensed to the ministry, though I have worked in ministry for nearly 10 years now. I just officiated my first wedding and will be doing another in January, both kilted and both in my Cian kilt because they were family members (and the USAK Clergy/Clark I have doesn't fit me that well). I will officiate another wedding in May and will more than likely not be kilted because the people I am officiating for have not asked me to be kilted and are not of Celtic/Gaelic descent... Personally I consider this part of my ministry to my friends and family and will wear whatever they would like. As for the actual tartan, I'll wear my best looking kilt if I do it kilted, and right now it's my Newsome 5-yarder in Cian.