The only priority/fast track option at EZE is buying the VIP Package from AA2000 (the airport operator). This will get you escorted through immigration and customs with no standing in line, plus some other "perks" that aren't worth writing home about.
Im not sure the overall service and convenience it provides justifies the cost but that is a very personal consideration. Check out the AA2000 website, last time I sent someone over there it was available in English.