I've done it before with my friend, I hosted a radio for a website on another vps that he owns. well but here is a different problem. that one was easy since all we did is created a separate page and the radio streamed on that page.
I have bought 2 vps this month, one has expired and the other one will expire very soon.
I want to install phpmotion I need about 700 mb of ram just for the php apache and ffmpeg and these things, i need to install sendmail to send confirmation email and it's easier to install and configure using webmin...
so about 700mb just for the setup and stuff, I need about 50 gb disk space, the bandwidth is not an issue
I had 1 vps from 2host vps e-class but didn't like it, chvps is good, so i wounder if i can get 2 or maybe 3 or even 4 vps for around 4$ each so the total will be about 12$ (cirrus 1 package) install the settings on 1 vps (webmin, sendmail...) and then the 2nd vps will be for ffmpeg conversion and the 3rd and 4th for the site to load? and the videos would be stored on all the vps after being converted, then I'll have 80 gb of disk space and good ram, for less money than 2host, would this work? if yes how?
Yes, it is possible. However, this is a rather general question that depends a lot on the specifics of your application (phpmotion) and the setup that the web host provides for the VPS.
Some are managed VPSs where you get root but the configuration is predefined by the host, most are unmanaged where you get an empty virtual machine into which you can load a standard OS image - the setup will vary for CentOS, Ubuntu, etc. Generally I'd suggest Debian or Ubuntu Server as those have regular security updates, whereas CentOS has been struggling recently. However you will have to use a non-CPanel control panel if on Debian/Ubuntu - Plesk is quite functionally rich, while DirectAdmin is a bit lighter-weight.
If you are a Linux newbie or don't have several hours a week for Linux admin (maybe 10-20 hours a week to start with), consider a managed VPS - this should include a lot of security lockdown, monitoring, etc, and will include a control panel.
I'd recommend Xen VPSs rather than OpenVZ or Virtuozzo, because a Xen guest Linux (the VPS) is really very close to a real machine, making it easier to use advice/setup from the phpmotion folks. OpenVZ/Virtuozzo is more of a lightweight container separating your processes from others in different VPSs.
Probably better to ask the phpmotion forums / list about how you can set up multiple servers for your requirement. Using VPSs, there should not be too much difference from a standard setup.