Firstly, I would want you to clarify your current status. What are you currently studying?hello.......................
Secondly, what do you exactly mean by career prospects of BS A&F with respect to ACCA/CA? Do you mean to ask how good a combination the specific BS with ACCA/CA would turn out to be or are you asking which one's better of the two?
As far as the difference between a BS in A&F and ACCA is concerned, ACCA is a well rounded course that covers subjects from Finance to Audit and Taxation. As the BS mainly focuses A&F, it is less likely going to touch upon areas other than fundamental accounting and finance. If you see yourself pursuing your majors in A&F from a well reputed university in Pakistan, I'd suggest you go with BS A&F from one of the good business universities in Pakistan that actually comprehensively cover the subjects in the modules they offer.
When going for a BS/MS program, it is very important to have a look at the course overview so you know which specific modules they offer.