RC makes 600 and 650cc injectors. Expect to pay a grip for them. MSRP is like $150+ a piece. If you can get away with 550cc injectors, you can look for the stock injectors off a TT Supra or FD RX7. The Supra injectors will be peak and hold, so you'll need a resistor box and the appropriate injector clips to run them. The FD injectors are saturated, so you wouldn't need a resistor box, but you may still need new clips. The injectors should fit into your rail and intake manfifold fine, but you may need to get new injector seals for the manifold, or bore out your stock ones slightly, since it'll probably be a tight fit. My DSM 450s fit right into my rail without doing anything to the seals, although it's a pretty tight squeeze. The stock rail and fuel lines are actually good to at least 300+ hp or so, so you don't NEED to get a new rail, but you'll probably want an FPR so you can mess with your fuel pressure to match the larger injectors. Oh, and I assume you know that you won't be able to run anything larger than about 310cc on your stock ECM. You can run 450s with an AFC set to trim injector pulse by about 40%, but anything larger and you need a standalone to get them to idle and run correctly. I'm sure you've already looked into that.