Don't know if anyone is interested but I just bought a set of official Yamaha Tenere Adventure Jacket and Trousers for �49 each on Ebay. Can't do links, but the item numbers are 130759187742 and 130770054391. Postage comes in around �15. According to the yamaha accessories page on their website, these retail at over �400!
They seem to have a number of jackets at different sizes but only XL trousers. No idea what they'll be like, but at that price they've got to be worth a shot. I need a replacement for my Akito desert suit that has seen better days (has been great for the price mind!).