Hi! On Wikipedia it says it‘s a trilogy [0], Misspent Youth being the one you didn‘t mention. Would you recommend starting with the 2nd book in the series?
[0] https://en.m.wikipedia.org/wiki/Peter_F._Hamilton_bibliograp...
[0] https://en.m.wikipedia.org/wiki/Peter_F._Hamilton_bibliograp...
Misspent Youth apparently is set 300 years before the 2 other books, and establishes the setting. The author does a great job of creating the universe in Pandora's Star so I don't think you need to read Misspent Youth.
I'd be interested to hear if you enjoyed the books. If you want, email me at the address in my profile.