Stripe Checkout build — instalments plus a delayed-start subscription

We're an indoor golf business in London launching a new coaching product on 1 November. We need a small internal sales page and a Stripe integration behind it. WHAT WE NEED A private page (one per coach, unlisted, used on desktop) with two simple screens: 1. Does the client have an existing membership — yes or no 2. Dropdowns for number of lessons, amount of practice, and payment in full or three monthly instalments On submit, generate a Stripe Checkout Session that, in a single card entry: - Charges for the programme — either in full, or the first of three fixed monthly instalments that stop automatically after the third payment - Creates a separate membership subscription whose first payment falls on a specific calculated date (the 1st of the month after the programme period ends), then bills monthly - Skips the membership subscription entirely if the client already has one - Records the selling coach as metadata - Sends an email notification to our admin team on completion Prices should sit in an editable config, not hardcoded. TECH Node or PHP, whichever you prefer. Can be standalone — it does not need to integrate with our WordPress site. We'll provide Stripe test keys and existing product IDs. No client data involved. PLEASE ANSWER THIS IN YOUR PROPOSAL Can one Stripe Checkout Session create both a fixed-length instalment subscription and a separate delayed-start subscription in a single card entry? If not, what's your approach? That's the part I most need to know is solvable, so a specific answer matters more than a general pitch. Also include a rough estimate, a timeline, and an example of similar Stripe subscription work. NOTES Low volume — around 15 to 20 sales a month. Needs to be live before the end of October. Looking for someone who does Stripe subscription work regularly rather than a generalist. Full brief attached.