The solution is to host the ENTIRE PSL in Pakistan next year and reduce foreign quota to 3 players. Quality > Quantity ofc.
Players who are willing to go this year would probably be fine with playing the entire tournament in Pakistan next year (assuming everything goes well iA). That means players like Duminy, Ronchi, Rossouw, Tahir, Morkel, Miller (World XI series), Tamim, Shakib, Fizz would be willing to come. They aren’t “shooperstars” but they are still quality players who will boost the overall quality of the league.
Add Mahmud & Mushi from BD; Tisera, Perera, Mendis, Angelo from SRL; Taylor, Sikandar from ZIM; may be Mac, Devecic, Shodhi from NZ; Holder, Lewis, Sammy, Simmons, Badree, Narine from WIN; Rashid, Nabi, Mujeeb from AFG; Jordan, Bopara, Moeen, Adil, Dawson from Pomland ...... and may be Amla - that's more than enough to keep 4 foreigners in XI. Besides, few other Poms, Kiwis & Aussies might come as well.
Players are not any issue - rather it's PCB & their presidential security....