IMO, the only injector cleaners worth anything are the ones with Techron.
Why would you replace all injectors? If they are dirty, pull them and have them professionally cleaned. I use Cruzinperformance.... good quality work, reasonable prices. Only time I replace inj is if they are hoplessly plugged / leaking . electrically open or shorted.
Yes, there are 6. High quality new injectors (i.e., not cheap chinese junk) arent cheap.