Need a server for woocommerce store.

[Tinferatto]

Hello, currently have a AMD Ryzen 9 7950x @ 4.5GHz (16 cores + HT) and 64 GB of ram. However, when I get about 250 users the site crawls and some users get an error 500 page. I have tried MySQL optimization and I use litespeed. I am sure it can get a bit better with better optimization but I need to have it up and running by Nov 1 and so I just want to get a big server for now or maybe a server for website and another for database. I am looking for something with 40 cores and 128 GB Ram, I run DirectAdmin now but don't really care about the control panel because there will only be two sites on it. Any recommendations? What can you say about Hostingsource.com dedicated servers? Are they reliable?