saimasood, i read ur post and felt like id written it myself! im moving in Nov to get married in Dec too, and am also going to start packing after Ramzan! AND i also live in London :) only two differences between us:
1) im moving to islamabad; and
2) ive been back and forth since i got engaged a few years ago.
overall, as everyone else has also said, u can pretty much find anything and everything there. but u dont want to have to shop around for things like cosmetics and lingerie after u get married, regardless of wat country ur in, right?? stock up on those two things for say 3 months post-wedding. by then, you'll have settled in and will start exploring the shopping there... hey, maybe we should start a "londoners in pakistan" thing and do our shopping together :) all the best!