commercial is easiest, agri is a waste of time and space as this race in my opinion, taxes can be the most profitable, remember to feed them of course, those poor starving virals eat a lot more than most, and loyalty will be a factor in your income.
and if you can manage it gain cg`s when you can from market, that will increase your profit if you go tax.
if youv`e not played viral and just trialling it then do commercial, like i said its simpler.