If you live in Pakistan for four years, your husband will still need a spouse visa to come with you to the UK but he will not need to live in UK for 2 years to be eligible for indefinite stay
( ILR ). He can pass the life in the UK test and apply for indefinite leave straight away.

If however you both decide to come to UK earlier than a period of 4 years, he will have to live in UK for two years on spouse visa before qualifying for ILR. As for the visa, it honestly all depends on how much money do you have. Since you don't have any job in the UK, you will need to have a good amount of savings to convince the ECO.

Good luck

 

Yes he can. In that case he will need to apply for the visa called FLR ( Further Leave to Remain ) which is issued for two years ( not much different from spouse visa ) BUT he must have his work permit valid for more than six months.

Good luck