Once they are archived they dont need to be under Vcenter but the server can be standalone
I got the (possibly incorrect) impression that FN-GM wanted a longer-term solution, as building the new servers, going into production with them and then permanently archiving the old servers could take a while. As such, a solution that requires temporary access to the features in the trial version might not be ideal.
Ah thanks, for what i want it sounds like to much work. Would be easier doing manual imports and exports.
You can't manage the free version of ESXi from a vCenter server, regardless of what your vCenter licences allow - you need the vCenter Agent on the ESXi host itself, and the free version won't have this. If you can use a trial fully-featured version of ESXi this would (I think) work, but you'd have to plan the whole project into 60-days and not need to rely on the features after that date.