|Then my vote would be option 2. I think most people will dread having to do a timing belt install in order to install this part and that may hurt your sales.
On a different note I have been working on releasing my first product for a while now and have gained an entire new level of respect for what is involved and the hours that go into it a project like this.
I have been using xometry.com to get my parts made. You can get instant online quotes from your CAD files and select different materials, machining processes, etc etc. It maybe worth looking into if you haven't already...and maybe you already have a better option. Just thought it might help.
Very anxious to see your end product!