OEM roof rack 2018 Prius Plug in

Racks aren't on the car now, but I assume the rear is narrower - so the rear is 36" bar width, front is a couple inches more.
The 36" is along the top part of the bar and should allow room for a strap running underneath still. I assume your canoe is widest at the middle and tapers - so it shouldn't be a problem. Shop around - we found our racks online, free shipping, no tax - much cheaper than local dealer.

 

I have the OEM roof rack bars. I did not look around at others, but the OEM bars are decent. They come with a torque AlanKey wrench. It will tighten up the rack to OEM spec no more and no less. Well you can tighten it less but that may lead to other issues for example if you leave the nuts loose and strap up something on the roof, it can cause the rack to pinch and not evenly distribute the load.

I like the OEM roof rack it matches the vehicle and fits decently well. They come with a rubber strip up top to give you something to grip on when you load the roof.

I did not shop around for an aftermarket brand though. I just stuck with the OEM brand. Be sure to retighten the bolt after a 30 minute highway drive. And then recheck the torque every 1000 KM or so. The alankey torque wrench can be tightened as much as possible and it won't over torque the bolts since it acts like a "torque wrench"