The ZPI group or performance group (I dont really remember their name try searching ZPI) has some really good internals. There have been some really good discussion on this type of thing in the past and I believe the verdict is that the engines are not built for much boost if any, but if your heart desires get some good internals to help hold it together.
It all depends on what you are trying to achieve with your turbo. Are you looking for as much power as possible? Or just a little more performance for your daily driver?
If you are looking for peak performance, I would skip Greddy all together. Not to knock their product, but I think there are better options out there now. Take a look at the stuff from Turbo Toyotas.
Now if you are just wanting a safely boosted daily driver, and you are on a bit of a budget, the Greddy is a great solution. First and foremost, make sure you purchase the intercooler kit. Second, find a competent shop that can give the car a proper tune for driving the car on the street. Also, get yourself a nice wideband to monitor your air:fuel ratio. You'll probably want to pick up a boost gauge as well. And a turbo timer wouldn't be a bad idea either.
If you want more specific answers to your Greddy kit questions, I would get in contact with Eloy from Race Precision. He has the Greddy turbo kit on his xB, and has done all of the custom tuning himself. Race Precision is also probably your best source for forged internals if you plan to bump up the boost on the Greddy, or go with a kit like that from Turbo Toyotas.
Yes, they do come pre-tuned. But this isn't necessarily the best tune for your specific car, in your specific location. Greddy uses a "safe" base map that should work for the majority of owners. It probably will not provide peak power or efficiency for anyone though. I would highly recommend getting a proper tune for your car and location.
You can also try contacting Eloy from Race Precision, as he probably has some base maps for the eManage that would be better suited for many owners. He has done a lot of tweaking on his greddy turbo. Both on the street and on the dyno at his shop.
yeah tuning is def the way to go, i was just saying it is not necessary at all w a greddy kit. i am on a base map for my civic with only a boost guage. NO INTERCOOLER ...per greddy, who is the resident authority imo on there kits, they tune the e manage SO safe and rich (i still get 34 mpg on my civic w kit on and DOGGING IT OUT 24-7) that i do NOT need a retune to add the intercooler either.
Just as an FYI, while you are correct tuning is the BEST way to go..it is NOT always the safest, nor is it the only. Per Greddy, their base tunes, are indeed vehicle specific, please do not be misinformed, however for your climate it is not specifically tuned.
Besides the final tune and gauges, you will probably want to pick up a new clutch or if you are running an auto toss on a tranny cooler.. as for internals the Greddy and ZPI kits are set up to boost safely using the stock parts.