Hello to everybody

Been a while since my last post but hey better now than never.
I would be looking for information on the following subject:

I practise 18th century reenactment and I have become bored to the american long hunter style that I have been doing for quite a sometime now and would like to turn scottish man of 18th century for the summer happenings to come.

My question is , since I am a lowbudget guy, at the website www.kilts-n-stuff.com I found many decent looking great kilts but then again they had something called "Ancient kilts" that looked allmost the same but not quite.
If I practice 18th century which one would be more historically accurate?

More or less they are both wrong (I guess) but which one is less ?

Thank you for your time

Richard_D