This is indeed the right section so no worries. The lowest possible would be 43 prayer 14 hp but you could also do it with higher hp lets say 35 and 1 prayer and 1 defence.
I completed it at 29 hp 1 def 1 pray for an order before. I had to get a second account to lead tunnels and climb down ladder into zombies first though. It's a challenge, but it's possible.
Ive done it on a lvl 29 before. The tunnels are a pain and so are the monkey archers. But for tue boss. Recoil rings when its on 2ish hp and you should be fine.