If you go to the OPG, search the main set you are looking for and bring it up (e.g. 1984 Topps), click on the number of cards link on the top right of the set break down, and then type in the team name in the lower search box (just above where the main list appears) and search the OPG will show you only the players from that team within that set. Hope that helps.
Yes, OPG has the team search function for most every set.
Not for some prospect sets, but I use it a lot to get checklists for the Giants..seems pretty accurate..
AS above, OPG, set name and then select the team(s) you want to see. IT includes inserts and parallels as well