I've never had ports for my temp probes, I just let the door sit on them and never had a problem. on my current build I may look into doing it tho. I'm just trying to figure out how to plug the hole once I've run the probe through it. I would probably have it done. if its a two door, go in between the doors, single door I'd get two temp meters and one on each end. wouldn't go through the door cause when you open the door it'll pick up the cords and get in the way.
I've been looking into the guru and stoker pieces but I don't think i'll add them to mine. I can't justify the cost, once you learn how your pit cooks maintaining temp isn't a problem.
with a bigger offset your gonna have to add wood to it anyways, and my cabinet cooker is fully insulated so once its set i never touch it anyways. so i really can't see where i personally would need it. that will come down to a preference item for you and your cooking style.