Style a slider and create custom video controls

Description

I've got a WordPress site that I'm creating a custom WordPress theme for.
I've got a slider which I've created using Slick slider. However, I'm struggling to style it so that it looks like the example. Ignore the video elements in the slider. It is the layout of the slides that I'm interested in here.
The second issue is that I'd like videos to have custom controls like in the Video Example attachment. The only difference to this design I'd like to see is instead of having a separate play and pause button I'd like the play button to show pause when the video is playing and play when the video is paused.
Where the pause button is on the example, I'd like a sound control element.
I can provide the play, pause & sound icons to you.
When responding please let me know if you will stay with slick slider or if you'll use an alternative method for the slider to ensure the styling is like the example.
Please ask any questions you might have and give me an idea on timings and cost.