I agree on the sporran. But to answer your questions, it really depends on the setting and context in which you plan to wear your kilt. Can you give us an idea on when and where you want to fit in? Also, what did you have in mind when you used the term "professional"?

A kilt can fit in with everything from a night at the pub to a state dinner with a monarch, so obviously the level of dress you anticipate needing will be important.