A bit of both, Wikipedia can often be outdated so Cricinfo is more reliable. A Google search pulled up a poster/press release for the Pakistan teams, in the one day cup tournament with squads, so it was just cross referencing them with the stats from the tournament to get the right players. Kits easily found with Google images and
@Llewelynf kindly provided images for me to make team logos from.
That being said, since I started doing a lot more on Ashes, I do probably follow cricket around the world quite closely. I'm familiar with players I'll never see play and know how many bloody Mohammad Irfans there are knocking about.
The Indian sides I did were taking a few top performing players from each major side in the Ranji and Vijay Hazare trophies with international players from the last two years thrown in. Then it was just a case of matching them to the region/zone.