Take both. Make sure that whatever brand you get that they are 100% UVA. You will find shades fine for the first couple of days and when you ski if it is not snowing. But goggles come into there own once it starts to snow.
Shades for the sun and goggles when the weather packs in. As long as the lenses have a UV rating doesn't really matter what brand. Just go along with your taste and budget.
A little advice. When you get googles for the bad weather go for a red, yellow or amber lense. brings out the bumps in flat light.
we took goggles, I didn't like them so bought some 'oakley' shades out there for about £2.50, yeh fakes, but so what, they were comfy, did the job and I didn't care if I broke them.
Do not use fake sun glasses. They provide no UV protection and cause your pupils to dilate thus increasing the damage done to your retinas by the sun reflected off the snow. Ever heard of snow blindness Ted? You have more chance of damaging your eyes wearing fake glasses than nothing at all! 'Yeh fakes, but so what? who needs thier vision'?