Okay I'm browsing their products, but I don't think Native Instruments makes soundcards.
I searched for soundcards and the only thing that came up was which soundcard is needed to setup traktor dj studio.
They list off many external multi-channel soundcards such as:
Echo Indigo DJ (PCMCIA - ASIO 2.0, Win, Mac, Mac OS X)
RME Hammerfall DSP Multiface (PCMCIA - ASIO 2.0, Win, Mac, Mac OS X, plus MIDI)
M-Audio Quattro (4 In/4 Out, ASIO 2.0, Win, Mac, Mac OS X)
Digiram VXPocket 440 (PCMCIA - ASIO 2.0, Win, Mac, Mac OS X)
Motu Traveler (Firewire, ASIO 2.0, Win, Mac OS X)
Motu 828 (Firewire, ASIO 2.0, Win, Mac, Mac OS X)
Echo Layla24, Mona or Gina plus extra PCMCIA adapter (PCMCIA - ASIO 2.0, Win, Mac, Mac OS X)
Audiotrak Maya44 usb
Terratec Phase 26 USB
Edirol FA-101
ESI Gigaport AG (USB - ASIO 2.0, Win, Mac, Mac OS X)
ESI Aqua U24M (USB - ASIO 2.0, Win, Mac OS X)
I'm assuming the external cards will be more expensive though.
They do list off internal cards too, though they don't state if they are "multi-channel". Is multi-channel the same as muliti-client?
Here are the internal card producers:
Aardvark, Audiotrak, Creamware, Creative, Digidesign, Digigram, Echo, Edirol, Ego-Sys (ESI), Emagic, Emu, Frontier Design Group, Gadget Labs, Hoontech, Korg, Lynx, M-Audio, MOTU, RME, SEK'D, Sonorus, Terratec.