The cheapest Roku is the "Express HD", which is a small box that sticks to the edge of the TV & is controlled by a standard IR remote. You then progress up to the stick devices, then with 4k & then with ever fancier remotes, all of which are WiFi controlled so you don't need line of sight to the device.
The age of the TV means it won't be 4k, so an HD device would do unless you have plans to upgrade it soon. If you do then most modern TVs will have all the aps you require anyway, & some even come with Roku built in.
@geedee Given you won't be wanting a huge 65" TV in your bedroom, you might consider an upgrade.
A 5* 43" 4K Ultra HD Smart TV can easily be bought for around £200 these days.
I set my 85 year old neighbour up with a Roku Express HD around the time that the BT Sport app closed down. It’s far better than fiddling about with Chromecast from his mobile phone as he’d been doing before. He uses it for his 2nd tv in the conservatory as he’s got Sky on the main tv in the lounge.
We have some experience in this area, having tried to run a TV in a room without an aerial by using a Roku Express instead. (The utility room, where we iron; it doesn’t look like the builder asked any women about this design, though the rest of the house is dripping with aerial outlets. But all driven off a central feed from a small relay station feeding the estate, as individual house aerials wouldn’t work here).
Now the Roku Express is a very nice device, does exactly what it says on the tin box, and we run several. And the broadcaster apps it carries all offer the live channels, unlike the ‘same’ apps on the TVs - including the TV we were using - and we lined up the apps, which Roku call channels, so they went BBC iPlayer, itvX, Channel Four and My 5 across the top, i.e. as close as we could get to a ‘Freeview channel change’ experience.
It was the apps that did for it, though; you could get into them easily enough with the above arrangement, but you couldn’t set a live channel and have that be there next time; every time we went back, we had to start from scratch and pick our way through the myriad other offerings the app had for us, just to get back to where we wanted to be.
And of course, no EPG.
What would have been perfect is the Freeview Play app I have on this iPad, which gives easy access to the main channels live, and provides an EPG; but the Freeview Play app on the TV is different, and doesn’t do that.
So, after struggling with it for a while, we bit the bullet and had our nice TV aerial people come and drill through the wall to pick up an aerial feed from the next room. So now this TV works just like the others.
So yes to a Roku Express augmenting a TV with an aerial, if that doesn’t carry the apps itself. But no to trying to replace a mini box with one, to get the broadcast channels. Maybe Freely will bring an advance this year, or next year, if Freely boxes become available, though.
But it still leaves pause and rewind live TV as the mini box’s unique party trick though, if that matters to you.