The best stories of them together imo are:
-Enemy of the state: Sturm Und Drang by Christopher Priest. They aren't married, but they do missions together, and you get a closer look into their history, plus intimate moments. Very well written (both their romance and the story arc itself). You can read the story on volume 2 of the Christopher Priest run (buy it at Amazon) which is a great read in of itself.
-Fantastic Four by Dwayne McDuffie. Storm and BP replace Reed and Sue for a bit. Very fun stories.
-See Wakanda and Die by Jason Aaron. That story is
in general, but BP and Storm have a very good showing together.
-Deadliest of the Species by Reggie Hudlin. The issue that led to BP's sister, Shuri, taking over. (The same story where Storm fights death to save T'Challa). Was a pleasant surprise.
You can also check out the BP Civil War tie-ins, which were pretty good imo.