SSD partitions best practice?

Hi all,

I have ordered the following:
- HP Microserver Gen8
- 16 GB RAM
- 4x 3 TB WD Red
- 1x Crucial MX200 250 GB

I want to use ZFS on the 4 hard disks (mirrored+striped)

But I want to use the SSD for the Proxmox installation, AND for L2ARC (and maybe ZIL?)

How can I create a EXT3 partition of lets say 32 GB for Proxmox, and give the rest to ZFS?

I have found an URL (which I cannot post due to forum restrictions) to resize the boot and swap partitions, but that's not regarding ZFS.

Thanks in advance!