what would i be looking for to spot a good injector compared to a bad one?
Smog on this board would know; he also has a pop-tester. He may even want to buy a few sets off you for his core exchanges. I'd be interested in a few sets as well.
Check for spray pattern; obviously if it's a fine mist, it's good. If it shoots a stream or if you see droplets, discard the injector, or preferably just the nozzle.
The OEM spec opening pressure for a 1.6TD injector is 155 bar. Discard the injector if you cannot restore the pressure above its wear limit. The max possible pressure for a 1.6TD injector is 160 bar.
If necessary buy some new nozzles from Smog or RedRotors; the injectors themselves may be OK and could just need nozzles to renew the spray pattern. Discarding the whole injector might be like getting rid of a whole Rabbit just because it had a flat tire

IIRC a pop-tester dedicated to injectors costs between $100 to $200 USD. Your idea of a "ghetto" setup sounds really spiffy though!