Nice setup Chris has there.
Any ole wood or alum pole or fiberglass rod will work for the Hiking Stick. In fact, a real a hiking stick is perfect for the job! A collapsable one works best. You do not need much length at all, 2ft or so will do it unless you also sit on the rear deck when you sail. Why?
On the port tramp you can reach the tiller yourself. On the starboard, just enough pole to reach across the hull will do it. If you use a boat hook or other long pole it's going to really get in the way as you slide from side to side. It will be hard to slip under the sail and sheet line if it's too long and you will have more trouble keeping it out of your way when seated normally. You want it to be "invisible" to you when it's not in use.
Figure out a "collapsed" length that is just long enough to swing the stick around the tiller handle and it won't hit or catch on any part of the cockpit, sail or seat. That's a good size to start with. If you can extend it once or twice from there, then it will work anywhere on the boat.
Again, a 2-3 piece hiking stick is a good choice. I use mine ALL the time to hike hills though,

so I found an expandable 16-30" windshield squeegee on sale and adapted that as my tiller arm.