First, don't worry about the "smart" features, they just get in the way usually. TVs are a more long-term investment, things like Roku boxes are often upgraded more frequently. Can you imagine using 5-year-old "smart TV" technology today?
Second, you didn't mention it, but I wouldn't get 4K (more properly called UltraHD or UHD) today. The spec isn't settled yet, and today's TVs likely won't be compatible with the future UHD spec. It will probably include an expanded color space, which will actually be more important than the increased pixel count.
Vizio is a pretty popular brand, and most people seem to get them at Costco. They're not the top-of-the-line brand, but that doesn't seem to be what you're looking for.