StarHalo
Flashaholic
4K doesn't need to be big or expensive, Wal-Mart had 49" 4K sets for $220 a couple months ago, and the big July sales start next week. Two points: If you don't plan on buying a 4K disc player/media (I haven't,) do peruse the slim online offerings as you may find there's not enough to warrant another TV. Also, note that Smart TVs are their own "Roku" and you can download and use apps with nothing else connected to the TV. I frequently use the Youtube app on my Samsung, it also has Pureflix available.
My Roku is an older Roku 3 from ~2015, totally worth it for the Adult Swim app, that's all it's used for anymore.
My Roku is an older Roku 3 from ~2015, totally worth it for the Adult Swim app, that's all it's used for anymore.