Two other contenders that I've used on many occasions for customers:

Celtic Crafts, 101 High Street, Edinburgh - http://www.celticcraftcentre.com/

Piob Mhor in Blairgowrie - http://www.piobmhor.dircon.co.uk/piobpages/enter.html

Depending on how soon before you travel, you don't need to wait to be measured. If you know what tartan you want then speak/email you preferred supplier and they will be able to get things organised. If you've 2-3 months before you leave then you may be able to collect your kilt when you're here.