Injectors I would go the ID 1000's. I have had the Sard 800's and my ID 2000's drive and idle better than the Sard's ever could. That was on a PFC and LINK G4. They will be bigger than you need for sure.
ECU: By the time you buy a FC and Nismo AFM's, you're almost at the money for a Link or a VIPEC. Go the Link or Vipec.
Water pump: Use a standard one. Its been covered quite alot on here.
Clutch: Some people swear buy them, having driven a few i'm not a fan. Nismo twin plate everytime.
Also a cheeky mod that you may want to do is the "Twin Turbo pipe mod". Have a search.