I think that from what i've read in the first act i would set this play in modern day new york. I interpreted this play as being a comedy that pokes fun at a lot of the era's social condition and think that you could make a great modern adaption. I would set Antonio as a stock trader and someone who doesn't really likes what he does but makes a living. His financial status depends on the luck of the stock market just like trade ships in Shakespeare's Italy. Bassanio is a college friend that wants to court this heiress and seeks the funds from Antonio. Portia is the heiress that Bassanio met at a club once or something and is set on dating. Shylock is another trader who may have some rivalry with Antonio and the character could portray any number of stereotypes held in our culture. The "crew" are just other friends either from college or fellow stock traders. Anyway most of the character types would transfer to a modern sense easily i think. The setting would match up quite nice.