Well the 'Islamic economic model' if there is any would perhaps rely extensively on trust, faith and good will which are largely absent from people's behavior these days
. Therefore the alternate to interest based capitalist economy is socialist counterpart which has problems of its own as it slows down growth etc. And also socialist economy would practically put too much authority in the government, something that must be avoided in case of Pakistan as we don't seem to have a sincere government. So let's live with interest and pray to God haha
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BTW I don't see any permanently designed economic model in Shariah which could be considered religious. There are guidelines which might help shape socio economic behavior and help shape the economy on Islamic principles but apart from that I think it's worthless digging religion for a divine economic model
. If we are true God fearing Muslims who are mindful of proper reasoning then our economic model is Islamic, else let's face this interest as a punishment haha. At the time of development of Islam the predominant mean of production was agriculture, it was neolithic age, today it's not.