Performance: ZIL & More ARC?

This is my first time installing root on ZFS manually, and I am using RAIDz1 across 6 256gb SSDs. All of this is running on an ancient dell poweredge R815 that I am trying to use as a desktop, so I am looking for performance gains where available.

Yes, I know it's not the best idea to use a server, but it was free and this is fun.

Here's the question: Would including a 32gb partition on an SSD for use as a ZFS Intent Log (ZIL vDEV) actually boost write performance?

Likewise, I plan on increasing the ARC size to 50gb as the system has 256gb of DDR3, and my normal use doesn't hit 25gb. Would I see a boost in read performance there as well?

If neither would make much of a difference, I will first try this install without for simplicity.