I don't have experience with the SoS mats, but bought a set of OEM tan mats off eBay for $100.
One thing to keep in mind is that the later NSX's mats are SLIGHTLY different from the ones which came OEM in my 94 (and I would assume your 93). At the bottom, the older mats have missing corners to accommodate the seat rails while the newer mats are completely squared at bottom.
As far as I know, the older style OEM mats are unavailable but if anyone finds a source please share with the group.