Executive summary:
"run the pioneer sub off of the stock amp?" NO
"Or does the stock amp not provide enough to power the sub effectively?" NO
"Or what do you guys recommend my best option is?" You have many options. They all involve aftermarket sub(s) + aftermarket sub amp.
PIONEER TSSWX2502 Power range: 100-300 watts RMS (1,200 watts peak power) 4 ohms
OEM Rockford Fosgate: 400 watts divided into 8 channels, driving 10 x 2 ohm speakers rated at 35 watts max.
I looked into him but he doesn’t ship to Canada so that won’t workDidn't Tech12Volts have a direct swap option? I haven't seen him around here in quite a while. It might be worth your time to contact him through his website at tech12volts.com.