Bear in mind that simply replacing bulbs, and most conversion kits are technically illegal and an MOT failure . A few types might not be immediately obvious and some people get away with using these. They may give glowing reports (excuse pun) but I think they rely on the mot tester not noticing, or turning a blind eye.(excuse another pun)
To remain legal may require complete new replacment headlight units that have been specially designed and manufactured with reflectors and beam patterns to suit led bulbs, and bear an led type approval marking. Probably quite expensive, if they are even made for your car.
Not sure what you mean by 'combating' other cars with more powerful headlights. At best you might be able to see a bit better, but it wont reduce the effects of brighter lights on other cars . It could mean you are both dazzled, with neither of you being able to see.
Especially if your headlights are not type approved.