You can do the fuel pump, but the injectors will have to wait. Honestly, the injectors are probably one of the easiest things to do on the install, should only take maybe 20 min. If you decide to tap the pan ahead of time, just make sure you plug it and don't use the return fitting, as the pressure in the pan will blow oil out of the return tube. I just found a bolt that matched the drain bolt and plugged mine until I could get to installing the S/C.
Congrats on the kit, you'll love it.