As to the name / content - I'll ask my nine year old and her pal tonight and see what kind of shop they'd like and get back to you. It is better to ask the ones who will use the shop I think. Have you thought about having a competition for the name for 5-18 year olds to enter, with them getting vouchers for your shop as a prize?
My daughter likes to shop at H & M as they have some good, trendy stuff. Have you thought about stocking any fairtrade products, or using the mail order to order for people? I think people would buy it if it was not enormously dearer than non fairtrade products.
Also, are you aware of free support through Opportunity Kintyre (
www.opportunitykintyre.org.uk) or that if you get bilingual English / Gaelic signage you can get 50% of the costs from a Gaelic development agency? Get back to me if you need more info.
Good luck.