VPS hosting is good and is somewhat comparable to a dedicated server
, only if it is provided by a very reliable host. It usually costs $60/mo for a befitting VPS. It may be advisable to move onto dedicated server for extreme performance.
By looking at specs of the dedicated server
you mentioned, I would say that it would be very sufficient for running windows 2008 server, IIS and MySQL. 200 thousand visits per month should be a piece of cake for this. However, it would be best if you also verify with the dedicated server hosting provider through their live chat. Though in my opinion it's quite enough.
It's imperative that you get your dedicated server from any one of the most popular dedicated server
hosting providers e.g. RackSpace(bit expensive), HostGator or theplanet.
You might also like to consider cloud hosting. Just Google " Amazon Cloud" or "RackSpace Cloud" they are extremely good in terms of service quality, and probably cost effective too, as you only have to pay for the amount of bandwidth that you use. I know a website with 20 million visitors a month (yes 20 M), it used to be on amazon cloud back then. I can share it's address with you, with proof of traffic, if you like.