Adventure experience booking platform with vouchers and rescheduling

We sell adventure experiences — hot air balloon flights, zip-lining, whitewater rafting, off-road expeditions and much more — and we need a proper online catalog where a client picks an experience, date, and pays in a few clicks. Right now every request comes by phone or messenger, and staff manually maintain a spreadsheet of dates and spots. We can't scale this way: we duplicate bookings, lose people who wanted an evening flight and didn't get an answer until morning, and can't sell anything when the office is closed. We need a platform where each experience is shown with photos, clear description, difficulty note and age limit, meeting point, and live schedule of available departures with remaining spots — so people immediately see what's free.

Booking must respect real capacity. Each session has a fixed number of spots, and the system must reliably reserve and deduct them so two buyers can't physically take the last spot at the same time. Payment happens at booking, with options for full payment or deposit. Besides regular bookings we need gift vouchers: a client buys a voucher for a specific experience or open amount, gets a code, and the recipient later redeems it on any session with free spots. Vouchers must have expiration, trackable status, and protection against reuse.

Weather is our main headache, so rescheduling must be built in from the start. When we cancel a departure due to wind, storm, or high water, every affected client must automatically get a notification and nearest alternative dates, plus the ability to reschedule their booking without calling us and without losing their payment. We also need automatic reminders before events, a simple load panel by session, and clean participant lists for guides. Please advise on the tech stack, payment integration, and how you'd reliably model capacity and voucher redemption.