I would personally pay the little extra and get the higher end model. I have owned a few different PV kilts. I have worn my 4 yard casuals to weddings and while it might look similar to a full wool kilt in a picture, it is going to behave differently. The higher yardage helps with this a bit and gives a better swing to the pleats.

You may also want to do have a gander at :
www.candiancasualkilts.com
http://www.burnetts-struth.com/sale_items.asp
http://www.scottishclansman.com/Readymade.html (proceed with caution with these guys)
http://scottishkilts.net/store/5_yard_kilts.html
www.westcoastkilts.com (check out the casual kilts- Rob seems like a great guy)
I am hesitant to suggest these ones, as they are so similar to stillwater (between an economy and a standard) but so much more in $$$$ www.canadakilt.com
and of course www.usakilt.com whom we have all heard the great reviews about.
Also check some of the rental places and see if they sell off old stock ever.

Either way, you should have no problem getting a Wallace tartan kilt.