We are doing these still, but in a different way. You need to send us a shifter to modify. The price from Nissan has skyrocketed to the point I cannot/dont want to put up the $$ to build these. But, we can modify your brand new or used shifter for $250 including return shipping. You can buy a used one, buy a new one or simply send us yours to modify. We can do these with a 48 hour turn-around. 
We start with your factory Nissan shifter assembly, and modify it by changing the ratio, get rid of the rubber isolator an add a weighted shift handle. The result is about a 25-35% decrease in travel (number varies a bit depending on how soft your current rubber isolator on the handle is). The knob height is approx the same as stock....you cannot visually tell the shifter has been modified at all. Installation is pretty easy 1, leave in neutral and unthread the shift knob and pop off the boot from the consul. 2, unscrew the inner boot and set aside (you may need to move a couple wires to the side) 3, remove the 6 10mm bolts and pull the stock shifter out of the trans. 4, unbolt the 3 shifter housing boot bolts and bolt the new shifter into the old upper housing. 5, place the billet riser onto the trans and put the new shifter assembly onto it...be sure to get the plastic shift bushing into the sift rod cup in the trans. 6, use the new allen bolts to tighten the new shifter onto the trans. 7, slide the urethane bushing off the new shifter and install the inner boot. Then slide the urethane bushing back on the shaft and use the ziptie to attach the inner boot top to the lower part of the bushing. Reinstall the boot and shift knob. 
Note; the sealant shown in the picture is no longer included...nor is it required.