What is the best preorder tool for high volume preorder (>100k) ?

In the past I used https://www.trycelery.com/ but it's dead, I look at if and find https://www.foxy.io/ We need to sell simple ticket access (15-20$) like eventbrite, but integrated in the page and with the payment only (Stripe checkout is also a candidate but there are limitations in transactions by second, 100 max) when you start.