Consistent Prize Images for Raffle Website

I have a raffle prize competition website & i need consistent brand related images for the prizes on my site, these will be square images, the prizes can be anything from Cash, vouchers, driving lessons, Pokémon, Xbox, iPhone etc..i will provide the images & the text & the category- there are 18 different categories (CASH, CREDIT, RANDOM, ESSENTIALS, TECH, TOOLS, TOYS, HOME, BEAUTY, LIFESTYLE, HOLIDAY, TRAVEL, PETS, TRANSPORT, SEASONAL, WATCH, MEMBERS & FEATURED) - I have been using Ai but the images are inconsistent - so need someone to create a standard theme & then variations per category - i may need between 10 & 30 images per month - i need someone creative - you will only be creating Jpg/Png images so Web design etc.. isn't required.
I will pay per image.