I would have to go with Riverkilt on this one. The Vietnam kilt with the green background looks great and is true to the ribbon. I would wear that one because my father is a veteran of that war. Being a veteran of Iraqi Freedom myself, I would wear that one if we could get it to look like the ribbon and still look good.
I have a fly plaid, in my clan tartan, that I wore to Iraq and used as a scarf under my body armor. I also wore my clan badge pinned to the underside of body armor. Both I wore for luck, but everyone in my unit knew that if anything happened to me, the plaid would go to my son, and the badge to my daughter. I made it back alive with no scars (none visible anyway) so I wear that plaid and badge on occasion.
On that plaid I have four sets of military ribbons. My personal ribbons that I earned myself are at the bottom. The next up are my father's he earned from Vietnam. The next are my father-in-law's that he earned during the Korean war, and at the top are my grandfather's from WWII. I wear them not as my own, but to show that my family carries on the Scottish tradition of fighting for freedom and to honor those who go before me.
What I'm trying to say is if you want to wear the kilt in rememberance of a family member or good friend, then good on ya. But if I saw a younger man wearing the Vietnam tartan, I would ask myself two questions.
Is that person wearing it for a family member or friend, or is he wearing it because he likes the pattern? If he's wearing it because he likes the pattern, then he doesn't know the true cost in blood sweat and tears, he didn't earn it, and shouldn't wear it. Sorry if I offend, but that is my humble opinion.