My personal opinion on the Mundorf Silver/Oil caps... they sound very smooth, cool, splashy. You will notice a difference, but to my ears they add too much "air" and I don't know if I'd like it for long. I put air in quotes because it's not real. I mean, it sounds like a coloration as opposed to natural.
In terms of the Tekdon Impact Monitors, I would rework the crossover before I upgraded anything.