What do you mean by it is having a hard time starting with injectors? If you want to replace your injectors that is all good and fine but make sure that is the real reason for your hard starts before you blow $1,000+ on injectors that don't fix your problem.
To answer your other questions:
An electric fuel upgrade is a wise move with any injectors, stock or hybrids and anything in between.
Stage 1's are a good choice if you plan to keep as much of the truck stock as possible. You can run the stock HPOP if it is healthy, stock turbo, tranny etc. Full force diesel has a good price and warranty on the 160cc upgrade. You will need a custom tuned chip though to get the potential out of them. As well as intake, exhaust, and gauges if you do not already have them. Hope this helps.