How to tell how many bots you can run on a vps

So i've been looking around at some Vps's and i've found a couple i'd like to give a go. My only problem is that i'm not sure how many bots i'd be able to run on them. In simple words, I don't know how to read the specs of the vps's and convert it to how many bots you can possibly run on it. For example,
How would I go about knowing how many bots I can run on this one?
Another one which the spec layout is different is Waveride · cheap vps · affordable OpenVZ + SolusVM in Europe
There's two more i'm looking at which are TrentaHost | DDOS Protected Virtual Private Servers (SSD) and cloudrino.net - Setup cloud server instantly

I'm just wanting to run around 2-4 bots right now. So if you've had any experience with any of these Vps's i'd love your feedback. But back to the original point, could someone help me read the specs? Thanks in advance.