Slot Game UI Design

Wanting to develop a 5-reel slot machine game. Seeking initial design help.
I understand slot games and the technical development very well. UI Design--not so much.

Game will have base game and 3 different bonuses.
One is a progressive pick bonus (must select 3 matching symbols).
One is where you have a free spins multiplier bonus. (12 spins where wins are multiplied)
Last bonus is a win-every-spin bonus.

Would love if freelancer has experience with slot game design.

So you have a visual...Ultimately, I want the end slot app to have the shiny feel of the All Aboard game (https://slotcinema.com/free-games/all-aboard-dynamite-dash/) and be fun like the Willie Nelson game (https://youtu.be/R7evbXSVe-A). Visually, I love, love the train symbols in All Aboard

Once we get the first design completed, we will probably do 1-2 variations. These games will be a gift for my wife. My goal is to keep her out of the casino.

Would like to know what inputs you need from me to make design easiest for you (and less expensive for me).

Please include samples/portfolio if you have it.

Thanks