My shower is 40 x 45 and I'd need the drain to located in the corner. What should I purchase?

wedi does not make a product with a corner drain. Your best option is to build a mud pan and custom order a linear drain from Laticrete with hook up in corner then at least it would be easier to float. Please feel free to give us a call and we can talk about your project. 800-938-7925.