how bout try the fuel pump relay first? its pretty straight forward. or you could check for fault codes? a simple search on google brang up this:
http://www.troublecodes.net/Toyota/ and it will pretty much tell you your troubles

also u can bridge 2 terminals on your diagnosis plug to by pass your fuel pump relay which, if the relay is f*cked will turn the pump on and the car will run (if it is infact the relay thats gone, which is possible just as likely, if not more likely than the fuel pump)
also theres probly more than 1 fuel filter, just after the tank so mite pay to change that 1 to.
the injector issue, a guy tried to tell me thats whats wrong with my cressida, but it seems unlikely that all the injectors would stop working at the same time, its more likely that just 1 will stop and u will only have 3 cylinders firing.
u could try putting on a pulse light to see if your injectors are firing when u are cranking, but as i said before bring up the ecu fault codes and it will tell u whats wrong, saves money replacing things untill u find the problem