I totally get you! Hopefully they'll make more movies in the future, but for now:
The anime from the 2000s covers the events of Shinsengumi Imon Peacekmaker (technically the prequel to PMK but considered essentially the same series, chapters 1-30!)
The first movie roughly covers chapters chapters 32-35, skipping chapters 31.1 and 31.2.
The second movie roughly covers chapters 36-42.
If you want to read on from where the second movie ends, you could pick PMK up from there! There are currently 95 chapters and the series is ongoing. However, I'd personally suggest reading the entirety of PMK when/if you have the time, just because the movies did unfortunately skim over quite a lot of really good content!
Hope this helped!