NME box wasnt/isnt sequential its a 6 speed h pattern.
the only way you would get a sequential gearbox is to buy a brand new xtrac/hewland/sadev etc and retro fit it to the gtir.
633 Rally Gearbox
Xtrac’s ‘633’ 4WD transmission has been designed specifically to cater for Rally cars competing under the FIA WRC & Super 2000 regulations, in series such as the Intercontinental Rally Challenge (IRC) and WRC championship WRC & S-WRC.
The gearbox specification meets all the requirements of the FIA S2000 / WRC homologation regulations and has been approved for use in S2000 / WRC championships by the FIA. To meet the FIA’s requirements Xtrac has achieved the lowest possible costs, whilst ensuring a technically reliable and lightweight transmission solution built to its normal industry-leading quality standard.
Something like this, but make sure you have about £30,000. as by the time you have a custom bellhousing, clutch, shifter, mounts, propshaft, driveshaft, cooler ecu etc etc
pretty pointless really....