I design everything at 4:3 because I run my CarPC at 4:3 as the ExAudio screen automatically scales it correctly to 16:9. It does not look squished or anything. 16:9 drivers and everything are waaaaaay overhyped IMHO. But there is no reason why you cant make it 16:9. You can make it 2000:1 if you want, it is all free to do.
Also the configurator does use windows forms, and I am in the process of making it tiny-resolution freindly but FCC does not. It uses DirectX. So no scrollbars, pages is how to do it. But if you make an object span multiple pages it is essentially static.
Easy to do.