You don't need a lot of hands. Run PokerTracker in the background importing hands from the HD every 1-5 min. Then PlayerView will put those on the screen. 100 hands is enough to at least give you something to go on. Also, by running 4 tables you'll often catch a couple fishermen on more than one table at once very quickly calling them out.

Simply knowing how many hands someone has called/raised pre-flop in the last 2-3 orbits and if they won/lost (helps estblish state of mind) can make all the difference when having to make close decisions like this.

Remember, poker is a game of information warfare!