High flow injectors, when I talked to Trent @ Chequered Tuning (great guy), he said it's a hit or miss.
Better to buy Nismo or Blitz injectors.
As for intercooler, just get turn-flow unit (piping that plumbs to standard piping) is the way to go and don't bother getting it engineered, Mr Plod and their friends may ignore them (that is the case in Victoria - I don't know NSW though).
Hope it helps.
Cheers
Grant