Hello,
Before I put my proposal, Do you know Shopify is a great project and took then 8-9 months to develop with only few features when it was first launched in 2004, and its been 13 years and they have continuously developing it. So, this will not a small project even if you have limited number of features.
Do you understand and agree with the point i just mentioned above?
You must also understand that few things like physical servers are not on my hand and i am not a server admin so you'll have to hire few different people for this project to actually work.
Now, If you're serious about it please contact me, I have a team which specialize in developing CMS only the coding part, but yes if you want we can pull this off. Feel free to ask anything about it.
Thanks
Meeshal k