Gemini Advanced vs ChatGPT plus

Hi there ,
I'm new to the AI world and i'm having a hard time deciding between gemini or ChatGPT

Basically my main needs are:

Building a custom gpt for work purposes, i want to make a work companion that will give me data from a prebuilt knowledge base, such as giving my pricing based on sales i make in my business. Does Gemini Gem is the answer for gpts?

image generation for graphic design

Day to day companion

Thanks in advance!