Well, Venus is about 1 minute of arc, and the sun is about 30 times that, in diameter. So by usual telescopic standards, it's pretty easy to see as a disc. If we think of eyepiece projection, a solar image of 6 cm will show the silhouette of Venus as a 2 mm disc, which should be plainly discernible. If you're using a binocular, it doesn't take anything special to display this. The only thing I would rule out is plastic body toy or giveaway items. Anything substantial should fill the bill, even those small "spotting scope" type things, which are useful at the beach ;-)
Having said this much, I should point out that it takes a little bit of practice to project a solar image with hand held binoculars ( I’ve been practicing. ) Of course, you have to point the large objective lens toward the sun, while you look at the ground or a wall for the image. The trick is the alignment. If you look at the shadow of the rim of the objective end on the casing of the binocular itself, you can quickly learn how it must appear to give an image. Just remember that the lens must be centered in its own shadow, so you’ll want to see one edge of this circular shadow positioned this way. It makes sense when you’re doing it.
It does take a steady hand, but then by slight movements you can position the projected image, for example into the shadow of your own body. So then if you have a flat screen somewhere, you can position yourself by your own shadow so that you can, by learned habit, put the image onto the screen based on this.
If you see a circle of light, this is the image of the sun, not the field of view of the binocular, which is larger. If you get enough control to move the circle around, you can find the edge of this field of view, where it disappears. To focus, just make the edge of this circle sharp. You will find it challenging to hold the circle in position while you do this, so you can try repeated adjustments with “reacquisition”. Be assured that the required adjustment is small, if you start with the binoculars focused at distance. If some wispy clouds should happen to pass over the sun, you will see that you are indeed in focus, if you have made the edge of the disc sharp. Of course this can all be done beforehand, and you will be ready to go.