I thought when you said it was pretty tight that the nut was on pretty tight, rather than referring to clearances around the nut (which is what you were actually referring to). Yeah, a nut driver can help. I believe park tool makes a thin-walled socket wrench. I have a couple sizes of 'em in my toolbox.
The one I have is CCW-2, which is actually a crank wrench (14mm & 16mm sizes). Park only makes CCW-5 now, which is a different tool.