Hey there!
Do you want an illustration that would go on the entire wall? Or a poster-size illustration to hang on the wall. If it's the latter then my price would be much lower. Anyway, do you have a list of all the characters you want and a description of what you want them doing, do you want any particular background? My process would be to do this by hand then digitize it, I would first provide you with some rough sketches for you to approve of then proceed to finalize it and vectorize it - If you initiate the chat I can send you some *watermarked* samples not available in my profile
Anyway, I could start working on this right now, just let me know!
Cheers!
Don't forget to check out my profile for examples of my work and my feedback
https://www.freelancer.com/u/certaintly.html