John, there's a lot to be said for having an echo sounder and someone who knows how to use it in the boat. Anderoo or Kappa are very good at it.
You find suitable fish holding areas - slopes, drop-offs, features, etc - or sometimes just areas which are at the same depth you've been catching fish at - and then you drift over them. You use a drogue to slow your drift. It can be quite hard if there isn't enough wind to drift, but that's unusual. A lot of the anglers use H-markers - these: https://www.anglingd...-h-block-marker - you drop them, the line unwinds until it hits the bottom while the float stays at the top. You drop one where you have found fish and then aim to cover the same area on your next drift.
You need heavy jigheads - you are fishing on the bottom in very deep water. A range from 20g to 50g would be sensible. And large, soft plastic lures. 5-6 inch ones, with stingers. Check the rules, there is a minimum lure size and last time I was there is was singles only for stingers, no trebles.
You don't need massively heavy tackle. 10lb braid is about right, 8lb or 14lb would be fine. The heavier (thicker) the braid, the more lead you need to keep in touch with the bottom.
You don't particularly need a very sensitive tip. I have a six foot Savage Gear vertical jigging rod. It's actually quite stiff, because it's designed more for giving action to the lure than for bite detection. Bites are felt through the rod or seen when the line goes slack on the drop. Nor do you need something as heavy as a pike rod. The rods you describe should be OK. Not perfect, but OK. If you want an actual jigging rod, you can pick them up for £30-£50, though they are a bit of a specialised rod to buy and you might not get much use out of it.
Once fishing, you drop the lure right to the bottom. Then you quickly lift it a foot or two, then lower it, following the lure down and controlling the descent. Often bites occur on the descent, and are indicated by a slack line before you hit the bottom. Otherwise you are feeling for taps. The bites can be quite subtle.
If there isn't enough wind to drift, you may need to cast and retrieve, jigging it over the bottom. That can be effective but it's a lot easier and more effective to jig vertically if you can.
This was a few years back in the boat with Kappa (and a terrible head cold).
There's a classic slack line bite at 6:10 - watch as the lure stops before it hits the bottom.
Should point out that we struggled for drift that day. We sometimes had to get it moving with the engine, but you're not allowed to troll under power. Just a matter of not taking the Mickey.