FYI - There won't be 5 class of fleets eventually PA5 will replace entire fleet, all PA1, PA2, PA3 & PA4 will be decommissioned.
Hopefully following information could help you somewhat...
PATH has a fleet of 333 cars that are in active revenue service. There are 4 models: PA1, PA2, PA3 and PA4. PATH cars are 51 ft (15.5 m) long, with a width of approximately 9'-2 3/4" (2.8 m). They can achieve a maximum speed of 70 mph (112 km/h). Each car seats 35 passengers, on seats that line the sides of the cars.
PA1 / Year: 1965 / Saint Louis Car Company / painted aluminum / Car No. 100-151 ("C" cars)/600-709 ("A" cars) / Total No. of PA1: 158 / "A" cars have cab units, "C" cars-trailers have no cabs, 2 doors per side / 139, 143, and 612 are out of service, 694 is a work service car
PA2 / Year: 1966 / Saint Louis Car Company / painted aluminum / Car No. 152-181 ("C" cars)/710-723("A" cars) / Total No. of PA2: 43 / "A" cars have cab units, "C" cars-trailers have no cabs, 2 doors per side / 160 is out of service
PA3 / Year: 1972 / Hawker-Siddeley / painted aluminum / Car No. 724-769 / Total No. of PA3: 38 / All cab units, 2 doors per side / 726, 754, 761, 765, 768 are work service cars / 745, 750 are out of service
PA4 / Year: 1987 / Kawasaki Rail Car / Stainless steel / Car No. 800-894 / Total No. of PA4: 94 / All cab units, 3 doors per side / 845 is out of service
Notes: All PA1 through PA3 cars were general overhaul by Morrison Knudsen in the mid 1980s. Cars 139, 143, 160, 612, 745, 750, 845 were left under the World Trade Center on 9/11/01 and survived the collapse. They are currently stored out of service and stripped of usable parts.
The Port Authority awarded a $499 million contract to Kawasaki to design and build 340 new PATH cars (tentatively to be called the PA5), which will replace the system's entire aging fleet. With an average age of 33 years, the fleet is the oldest of any operating heavy rail line in the United States. The Port Authority announced that the new cars will be an updated version of MTA's R142A cars, which are currently in service on the New York City Subway's 4 and 6 lines. These new cars are expected to go into service starting later in 2008.