Affordable AMD Ryzen dedicated servers?

Hello,
currenlty 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 GTHost.com dedicated servers? Are they reliable?

As an alternative, try considering Shifthosting.com dedicated server packages. I love how easy it is to manage my hosting.
Their national IP transit network offers high quality, scalable, and affordable bandwidth & connectivity. Intuitive interface that makes everything easy.

Was impressed by their uptime, speed connectivity and professionalism of their support techs.
Like GTHost.com London servers - They offer 1 hour response guarantee, but I can say that they reply in 10 minutes after support ticket sent.