The dual head setup on my creator pro was a pain to keep aligned and leveled. I'm in the process of implementing similar Y coupler mechanism for the creator Pro printer. But for now, if you want to just print using 1 J-head bowden setup, this coupler is enough.
The kit includes a fan duct (the heatsink cooling fan acts as the part cooling fan). the fan duct comes in 2 pieces (print separately and press together as shown in images).
The extruder mount simply fits directly on the existing carriage assembly and re-uses the screws from your existing OEM extruder assembly.
Use the E3D V6 extruder.
Follow my project here: https://crunchysann.com/BL/projects/