I take a size 13 as well, and the best shoes I've ever used are the Nike Kobe low-top basketball shoes. They're all kinds of awesome and I highly recommend them - they're much better than anything Yonex have put out.
In fact I like them so much I just bought another pair.
If they don't float your boat though, the Adidas 'Feather' shoes (either the badminton or tennis models) are worth looking at. The new Feather III tennis shoe is great - I almost bought it.