Brainstorming - Help with my server migration roadmap

First, sorry for the long post

I have in my rack 2 servers in production, one freenas 9.10 with an fx3820 and 32g of ram, 5x3tb hdds, and a 10g nic. This server has quite a handful of plugins and jails running in it, responsible for everything from backups and media streaming to home automation and even email hosting (yes, multiple domains) via postfix and dovecot.

Second server is esxi with ancient 6-core opterons that, all together, benchmark as well as a current gen i3. But it does have 128g of ram. And 5 15k sas drives. And it's a jet engine. It's my testing server, use it mainly to spin up vms of things I want to try out, test networks, exchange servers, etc. It's only production thing it does is a windows 10 vm with a pcie pass-through to an r9 290 gpu, used for steam in home streaming over my openvpn server. (which is actually super stable, use it for lan parties and even used it while I was in Hawaii with descent success)

As we know, freenas 10 is on the horizon, and I will need to migrate all of my jails and all of their configs, databases, etc, to new containers or VMs. Also, I recently acquired two xeon e5-2670s, 64g of ecc ram, and another set of 5 3tb drives, waiting on the board. In addition to migrating the jails, I'll need to migrate it to new hardware as well. (which may actually make things easier)

Here's what I want - everything under one physical server and minimize my rack. I don't know how to approach it. I'm stuck between having everything run virutally (even freenas) and having freenas handle all the vms. I'm sure there are other ways to approach it as well. One thing that worries me is device pass-through, which I will need for my windows vm, and I'm not sure if freenas 10 will support.