The correct one is the QP-2HC, the QP-2H has a double shaft (front and rear) while the correct is single shafted.
Can you tell me how much they ask?
I was in contact with Ian, the Über2Nxt maker, and found a source for the sensors.
Another guy started collecting orders for sensors, Über2Nxt and other parts because Ian ask for a minimum quantity to start production but they done it at the http://www.frugalsrefugees.com forum but the site went down last year.
I'm still interested in some parts and if other are interested too we can try to rise rise orders and reach a reasonable amount for Ian to produce.
I've attached the files that describe all the parts that Ian makes.
P.S.
Ok, I just managed (unexpectedly) do get the file where he annotated the orders nicely along with forums name so I may be able to contact them to see if they still interested. Nxt.zip