If you go with Roku, be sure to get the right box to match your needs. Some are wired and some wireless. Some support HD and some are standard definition. Get the HD version and you get HD content when available.
If you need an antenna amp, get a Motorola. It has worked flawlessly for me the last 6 years. They come with built in splitters so you can get one that supports 2 TVs and another with 4 TVs. Maybe more.
More helpful information. Thanks