PokerTracker

I'd like to see how a player in my database is playing only against me. Both by looking at their HUD in the HH replayer, as well as creating a report with other stats. How can I go about doing so?

That will require custom statistics - see this guide for the basics on custom statistics creation and this guide for a deeper walkthrough. While the latter was written for PokerTracker 3 and the user interface is different the techniques still apply to PokerTracker 4. There is also a thread here on the topic of 'vs Hero' statistics and an example of that type of statistic available in the Download Warehouse called '3Bet vs SB (Hero) Open'.