CRT .5 shock option?

GO: yeah i looked on nitro house to try to build it the way that site talked bout...but couldn't find the actual shock cylinder, part number 40737. :( and just had to once again rebuild the front shocks...though on nitrohouse the part 40736 is the shock shaft, and 40737 i'm guessing is the shock body. NM i found it, but now i'm try`n to get all the parts that they ahve listed to order, and cant figure out if i need more than one on some of these or not.