Originally Posted by The dream of rain

The above books are, for now, sufficient, but after you are done with topics covering by these books you can go for "Muslim Political thoughts and World Constitutions."
But, to be really honest, i did not find "Muslim Political thoughts book by M.Aslam Ch.," up to the mark. If you find its replacement, do tell me.

Lets answer your query:
1. Political Science theory and Practice is sufficient for, part-2 of paper-1, topics like, liberty, state, forms/ systems of governments etc... It also highlights few Muslim thinkers so it will offset absence of "Muslim Political thoughts book" to certain extent.
2. Constitutional... history by Hamid khan is good to cover Pakistan post partition area, judicial, constitutional and political history and issues. (That means Part-2 of paper-2 specifically its Pakistan related aspects).
Plus, it also includes comparative analysis of all 3 constitutions, 1958,'62 and '73.
3. Sages of Ages ( i have not read it, but a friend who did, said, it covers "western political thinkers' part." for my (western thinkers') preparation i preferred book by Judd Harmon's book.) For this book other members may guide you.
4. World constitutions book covers political systems and Constitutional comparison part (paper2). (since you don't have it, right now, use above books for remaining syllabus)
Hope it helps!