Definitely going to need a computer to have it tuned, don't think you had one on your currently equipped items list. .
Injectors, I thought, were a must but Massive is saying he made a similar figure without them, I'd not heard of that before and I think I'd rather shell out the extra bucks then lean too hard on the stockers and risk leaning out.
What duty cycle are you injectors on at that power Massive?
At this power you're starting to push the bottom end so reducing the risk that anything else can go wrong, like running lean on maxed injectors, is a good idea.
Ben at RacePace is widely regarded as a GT-R modification and tuning expert so he will have his own opinions on this too and has proven his expertise time and time again. A quick call to him might be a good idea too.