Now, I haven't VPS, I must bought it between few days, because I must move about 5 - 7 Wordpress Blogs.
I will take a "managed" VPS, but I am not very expert with manually configurations of server, and settings of PHP, MySQL, etc.
So, I am searching where find the best settings and optimizations for my VPS to speed up Wordpress, and have good performance. (after I will request at the Hosting, to follow and set those serttings for me).
I will use CentOS as S.O, Apache Web Server and Cpanel/WHM as Control Panel.
Well since you are going to get a Managed VPS , you can let the provider know to optimize the mysql , apache on the server before receiving the VPS from the provider. The provider should be able to provide it with your requirements.
I just moved a bunch of Wordpress blogs over to a custom VPS at ioflood.com, and the performance has been amazing. Ask for Gabe. He did troubleshooting, optimization, security, and everything else I needed to make it a smooth transition.
If you can get it, SSD space for mysql is a big plus for a busy wordpress site. There's obviously a lot of other optimizations you can do as well, but you'd be surprised how much of an impact that can make.