I would just get a signalab 16s bms myself. I've come to like the blinky led's that show you when it's fully charged and balanced. If you want to really pull huge power like 100 amps, I would not use a bms per se, but rather some kind of low battery warning device. That way the humongous power won't have to pass through fets on a bms. But a signalab bms from ping would be fine for 30-40 amps. Just email ping and tell him what level of amps you want to be using. He has stock bms, or higher rate ones for 40 -50 amps.
But more and more, I do practice at least some minimal monitoring of my pingbattery. While it was new, I used a cycleanalyst with it so I always know pack voltage and how deep I discharged it. Now that my ping is getting old and tends to unbalance a lot, I even added some 8s jst plug ports to the wiring so I can check every paralell cell groups voltage with a cellog 8 in just a few seconds.
I try to dilligently type cell or paralell cell group depending on my meaning. But it gets tedious, so often enough many of us just say "cell" when refering to a group of paralelled cells in a battery pack. Once paralelled, the group more or less behaves as one cell. So you got it right, no matter how many p cells in the pack, you only need 17 wires to monitor a 16s pack. One negative, one positive, and 15 that are both + of one cell, and the - of the adjacent cell.
Best approach of all is use a bms, but still monitor the battery. Using the bms allows you to practice deeper discharges much less risk of overdischarge of a single paralell cell group. But still monitoring the battery manually allows you to smell a rat if the bms fails to stop the discharge when it should. Kind of like having a belt and suspenders on your pants.
Running without a bms is really best only for applications that require huge amps, and using the "fun" budget where lots of time spent fiddling with montioring, and even battery destruction could well be part of the fun. Transportation budget, you want batteries to last a long long time by the use of conservative discharge rates and depth. Then the bms is highly recomended.