One could write about 50 pages to answer your questions, because so much is context-dependent.
Very briefly, and not taking into account pilot skill:
Upward style
If you're looking to force an increasingly tight spiral climb, the Niki would be better because of its superior low-speed manueverability with flaps deployed. The idea is that you are eventually sacrificing your climb potential to tighten an upwards turn that you know your enemy cannot follow. But if you are looking to ultimately gain the perch, the 109k is a better climber and better as a pure vertical fighter. However, I've always felt that the 109K fights better from below than from above.
Dive Style
The 51, if you are the aggressor. The reason is that its high speed flaps deployment allows you to quickly bleed E and increase your turn radius if your victim decides to induce increasingly tighter turns. However, I'd say it's the 190 if you are defending, because of its outstanding roll rate.
But for this example I am picturing a close in engagement. If you are talking about BnZ, I would recommend the 190, simply for its cannon snapshot potential and its ability to recover E vertically if you bleed too much on your passes.
