Custom booking and reservation workflow for a multi-language hospitality site?

Hey everyone, I’m currently developing a custom website for a boutique hotel client using October CMS. They need a highly tailored booking workflow, localized room availability calendars, and a multi-language frontend switcher.
As a reference for the exact type of traditional hospitality layout and structural look we are trying to build, you can check out this live Austrian alpine hotel site: https://hotel-weissbach.at/. They have a very clean, image-heavy layout with distinct sections for rooms, regional activities, and direct inquiries.
Instead of relying on heavy third-party external widgets, I’d love to build this natively using October’s custom components and RainLab.Translate to keep the performance lightning-fast.
Has anyone built a robust, custom-tailored reservation system on October CMS recently? Would you recommend handling the booking logic completely through a custom plugin using a dedicated database schema, or is there an existing marketplace plugin that handles high-end hotel localization and direct inquiries smoothly out of the box?