Ebooks, PDF builders, and Sketch?

Hello Hunters, I have a few questions on the best products/workflow to build and publish a book with custom graphics I made from Sketch. Here's a technical summary: 1. Book formatting - Currently, I'd prefer to stick to an A4 printable copy as the Sketch graphics (1080x1080 canvases) fit in a 3dpi canvas (1500x2400) enabling readable typography for long text formats. Testing it out on my phone and ipad, I'm comfortable with this format and plan to at least make one Printer-friendly version, however.. 2. Sketch exports - To my understanding, CMYK is not an exportable format with Sketch and this will effect the printed version, but not the intended digital version. Most of the material is in black, white, grey, and 4 primary colors, and fairly easy to convert/recreate in Photoshop or vector equivalent. However, that's over 100 canvases and leads to the need for a stable production environment before completing. 3. PDF maker - With the text written and graphics made, I originally planned to export the 3dpi canvas sequentially, and then ran out of ideas on what to use to combine into one large ebook. I have yet to check products on here that fit the description and figured this might be the best place to go before using SEO recommended apps. With the above considered, what would you recommend in building the book and consider for later publications moving forward? Thanks!