You have a lot going on here i would having a conversion with your NetApp partner/ NetApp account team for your options, but no matter what you end up with, you'll be going to Data ONTAP (cluster mode).
Do you plan to keep a MetroCluster config? There's now FC and IP based metro clusters on various platforms .
And there is not really an upgrading the hardware either, you'll end up building new along side your existing and migrating to it.
But still, I would have conversations with your Account Team.