I'll add my opinon on staffs and lengths.
A dear friend made me a custom wading staff out of a closet rod. He put a plastic tip on the botton with a metal carriage bolt run up the center to keep it from splitting from use. I've never slipped on a rock when applying LOTS of pressure on it - and I'm glad it's there.
The handle is wrapped paracord which I attach to myself when wading and it floats next to me when not needed or I fling it over my shoulder and it's just there waiting for me to need it.
The trick to wrapping a paracord handle is to (1) remove the inner core and (2) SOAK the paracord in water before wrapping the handle. Then as the Paracord dries, it shrinks just a little bit to firmly adhere itself.
As to length - I like my wading staff a little long - so I have paracord wrapped from about 4" from the top down about 18 inches - so I have lots of room to grab hold regardless of the terrain.
Think about it - the creek or trail is seldom level - and lots of times I've put my wading staff into an area much lower than my feet and then used it to help balance myself in/out of uneven terrain. Having the little bit of extra length has been very handy.
If you have a friend with a wood lathe - have them turn a "knob" that you can glue over the end of the staff so you can put your weight on your hand and lean on the end of the wading staff - made a huge difference for me.
Also - my friend added "measuring lines" along the wading staff for me using rod wraping techniques. I have lines at 6", 8", 10", etc so I can quickly measure a fish since my wading staff is usally floating next to me and do a quick release.