VPS or dedicated Host for 250 visitors per sec?

If you want to know whether a host can handle that load of traffic, try a load testing service. Sign up for a free trial of any vps, then https://loader.io/pricing

OP, i have a website that do 100k a day, and sometimes more than 400 people online. Am hosting with servikus (Premium hosting). You can check them out here: http://servikus.com/premiumhosting

Also, they have a thread in BHW and currently a 40% off for recurring payment is running. Just moved some more of my websites to them from bluehost. My site even though it has that many traffic. It loads less than 3 seconds.

Thank you all for answering,
I think I'll start with VPS .. and see how it will work
What company have good service for VPS?

It all depends on how good are you at optimizing servers.
A VPS with 1-2GB RAM can handle that much traffic.

Yes, VPS will be the perfect match for you. You may try offshore seo vps for cheap plan. And the vps with 2 gb ram will be perfect to handle those traffic.