Question about Virtualization: CI vs HCI

I am at a point where I need to upgrade my storage as well as VDI infrastructure.  Currently it is a CI setup with the following pieces that make up it up.

• 2 x HP ProLiant DL380 Gen7 (w/o any 10Gbe), 144 GB RAM, Dual Socket and using a non-persistence disk for VDI.  There is no local storage of the vhd. running on XenServer
• The server layer of the environment is running on 3 x HP ProLiant DL 360 Gen8 w/ both 10 GB over Fiber and 1 GBe.  These hypervisors run VMware ESX 6.0.  256 GB RAM, Dual Socket.
• This is all connected to a Cisco catalysis 4507.
• The storage that has very limited storage left is a Netapp 2240 with a mix of 7200 and 15K disk on two different agg.

So the question is do I move to a HCI and stay on a CI model?
I had reservations about HCI because I thought I would lose my VMWARE investment, but that is not true from what I was told.  After my conversation the other day I am thinking HCI might be a good idea.  
I think some of my issues is my data set of 50 TB. It is a mix of unstructured data (37 TB) and block level data of 13 TB.
I do have some really old data that should be moved to cold storage to remove some of the tension on the storage unit and help make a decision on new storage technology.