first question is YES
Second question matters on what you want out of it. You could use the stock IC and fuel if you really wanted to, it just wouldn't give much gains.
Personally, I think buying a turbo is silly if you're going to use stock injectors. You can pretty much max them out on the stocker with far less lag. Why are you so resistant to keep the stock injectors? They cost a lot less than a turbo swap!
Also, why are you going STi TMIC? It's pretty small even for a VF39 let alone an 18G. If you're buying something new to begin with, might as well get something a lot bigger.
If you're trying to do this on the cheap, a better bet is used VF39/43 + used STi TMIC + fuel pump + pro-tune
04 STi 16G powered lagless fun
04 WRX: SOLD