yes xtreme vision gaurentees 100% more light on road, so surely improves visibility and uch more then these chinese HIDs, availaibility is an issue fr sure, in karachi yes they may be availaible and lhr aswell but you have to search for them, i got them from UK and they would cost you around 3500-4000 rs a pair, as for the projectors headlights, well they are avail the bi xenon projectors (chinese) and they would cost yu around 14000 rs, but they are also not tht effective as they are chinese and dont offer good quality, so you gotta have some good stuff, and also for installing tht bi xenon projectors you gotta open you original headlights and get them installed, and i am not for it (my personal opinion though), but you can get a pair of used headlights and get them installed, but in my opinion the best option is to get better halogens and stick to them....
cheers happy conversion