Make sure you set your TPS back to .46 volts with throttle closed and key in the on position (car off) then use multi metre and probe the positive up the back of your TPS plug, im not 100% sure which of the 3 wires is power on a NEO motor but on my S1 its the middle but just double check.
as for the coupling in-between tb and j pipe, just take the old one off and take it with you to autobarn, supercheap whatever your go to is and match it up. Those places stock what you need