It is very strange that the VPS host does not say what is the RAM allocated to the account. Your contact should be able to see this in the VPS management panel. What kind of virtualization does one use?
I would not suggest one to go for a Cloud server, un less he or she know what is doing? It might prove costly as some cloud providers charge for each and everything on the account. He’d better consolidate everything on a good dedicated server. What kind of content does one host on both instances?