I currently have a pair of Union 6 Supreme and Lii Audio Fast-15 drivers in a ported cabinet. I use a Decware Torii Mk IV and occasionally a Gromes Phi-26 (SET or SEP with EL-84 output tubes). Can't speak to the Ohm or the Pearlacoustics but I'm sure both would also work great.
For what it's worth, the Lii and the Zu share some similarities but are overall very different sounding loudspeakers. Both are predominantly front row, midrange forward presentations, image 3D and benefit from subwoofers to my ears. The Zu are clarity and tone queens and have greater extension to the frequency extremes but don't feel unbalanced. The Lii (depending on how you implement them) are just an all around pleaser with a little more euphonic tendencies than the Zu. Amazing what 15" single drivers can do. Easier to pair the Lii with a wide variety of amps. The Zu U6S are more picky. I could live happily ever after with either but I'm glad I have both.