Linux wifi hardware that supports many managed interfaces

I need to aquire hardware (can be a wifi card or a router) that is capable of simulating many wifi stations on one wifi radio. Something similar to this (from arch linux wiki):

$ iw list

Wiphy phy1
...
        valid interface combinations:
                 * #{ managed } <= 2048, #{ AP, mesh point } <= 8, #{ P2P-client, P2P-GO } <= 1,
                   total <= 2048, #channels <= 1, STA/AP BI must match
...

I have discovered that i need a SoftMac device, possibly with ath9k driver, however i have not been able to find specifications for any hardware that supports this. Ideally it needs to support 20+ stations. Any recomendations?