Is a “Man Bag” (messenger bag) Recommended with a Suit?

Leaving out the part that wearing a bag make you look less manly, that’s another discussion, from style perspective only if you have decided you’ll wear a man bag (high-end leather messenger bag or leather accented camera bag – ipad sized) for a casual (non-formal) dinner should you wear a suit?

If the answer is yes, how about color matching, what color suits are recommended for a brown leather bag and what for a black leather bag? What color with get more miles?

Also if the answer is yes, how about a more formal gathering like a wedding?

If the answer is no, the only other solution is a briefcase, but briefcases are too big generally (most you can fit a 15″ or 17″ laptop), do you know one close to an ipad in size, or if that is impossible, for a 10-12″ size ultrabook/netbook?