I am not a installation specialist but to answer your question on a more general level:
- Here the link you're after: Migration
- What needs to be done will depend on the existing environment (eg. SAS modules installed, number of environment, virtualised or not,....)
I would assume that even if the current environment is virtualised the underlying hardware will change so just moving the virtual environment from one data center to the next is a rather unlikely option (and I would assume the "old" data center loosing the customer wouldn't give a lot of support anyway).
If you have to install the SAS binaries in the new environment: We're now at SAS 9.4 and this is the version which will be around for quite a while. I believe it would be best to directly move to SAS9.4 in the new environment. Especially if there is also a mid-tier involved then having SAS9.4 would be a real advantage (as in SAS 9.4 the mid-tier is no more 3rd party).