PokerTracker 4 (PT4) consists of two separate products (Holdem & Omaha) integrated into one application. Both Holdem and Omaha come with a free 14-day trial which we highly recommend that everyone takes advantage of prior to purchasing.
GGPoker do not permit the use of a HUD and PokerTracker 4 does not import live hands or display a HUD on GGPoker so that shouldn't be an issue however I recommend contacting GGPoker support to seek further clarification.