I'm basically at the same point you are with the fuel lines and pumps. I'm currently using denso 850cc injectors but I'm thinking about picking up some of these from Snake Eater Performance.
https://www.snakeeaterperformance.com/p ... 1000cc-min
I watch a lot of YouTube, like more than is healthy. One of the channels I really like is Sloppy Mechanics. He mainly deals with LS stuff but hes been testing SEP injectors for over a year with no issues.
Other thing is, are you upgrading the wiring for the fuel pump? I just dropped in a denso unit for a supra TT that flows around 280lph. After doing some reading up on it I started to get a little nervous the stock wiring wouldn't be able to handle the 20 amps this pump wants.
I don't know what the stock wiring is but it looks to be around 14 gauge? I ordered some new 10 gauge wire and a 30 amp relay and fuse holder. I'm just going to use the stock wiring and trigger the relay off that. My battery is already in the trunk/hatch so its only going to be like 5 feet of wire.
Oh one more thing, I'm guessing the capacitor there is to smooth out any electrical noise the pump makes. It might also be there for any kind of a sudden surge like when you first start the car.