Thoughts on next Upgrade

Hey Folks. I have the 30% upgrade offer and felt it was time to upgrade my current setup.

My current living room setup includes

1. Arc
2. One SLs (front surrounds via sonossequencr)
3. Era 300s (rear surrounds)
4. Sub 4

I was thinking of either upgrading the Arc to Arc Ultra or the One SLs to Fives.

I’m not sure which one to do. Wanted to get a second opinion. What would you do?