Cisco Catalyst 9130 and 9136, Meraki MR56, Ruckus R730 and Aruba 550 does 8x8:8 in 5GHz. Probably several others as well. But i don't know of any 802.11ax clients that support more than 2x2:2
Aruba only does 4x4:4 HE160 or 8x8:8 HE80. Ruckus looks like only 80Mhz as well.
Cisco: PHY data rates...