Here's the course description: Covers prose, poetry and drama of the post-Renaissance period through the Restoration with special focus on works of John Milton.
The big focus in the description is on Milton. To me, that means we're going to read a fair bit (and maybe all) of Paradise Lost, and also want to read the big poems.*
The Norton has the whole of Paradise Lost, but no Samson Agonistes.
The Longman has chunks of Paradise Lost, but only Bks 1, 2, and 9 in their entirety. And it has Samson Agonistes.
I'm going to have to go with the Norton for the 17th century class.
*I have a true confession: I've never made it through Samson Agonistes. Never. Yep, I should probably lose my credentials for that. Maybe I'll give it a go this week, and see what I see?