Well, i just finished a turbo conversion on my 2.6L. I know it's a different engine but the problems in these upgrades are the same...
Fuel pump: Flow and not pressure is that you need more. Pull of the fuel line from the fuel rail, send it somewere you can measure the volume, and turn the key. You should measure at least 2L/min. If you have it then no new pump, fuel lines etc. -and you keep the money
Malpassi regulator: you need one of these... 40psi is ok
Programmable ECU: YES, YES, YES! If you want a clean job and your engine running like stock, there is no other way. Put a MAP sensor too, because MAF sensors have problems at the high air flows of a supercharged engine.
Fuel rail: I really don't understand the problem with the fuel rail. I know quite a few cars with over 300hp and they run the stock rail. The guys above say that there is an issue with it and they changed it. Well, if you want peace of mind change it...
Injectors: 300cc is a must for 200+hp. If you buy used injectors clean them in a qualified shop and make a volumetric check because they must spray the same amount of gas! THIS IS IMPORTANT! You don't want to have an injector to inject less gas in a cylinder than the others (=blown piston)...
Ignition timing: When boost pressure increases, the advance timing must decrease. Moreover the compression ratio of 8.9:1 is a bit high so the advance timing map of a naturally aspirated engine may not be good (=high temperatures=blown engine). This the main reason that i hate the fuel managment units that work with the stock ECU. They are ok for a few hp gain but if you need more you just can't change the ignition timing map and you're dead... Stay away!
Wideband lamda (oxygen) sensor: you don't really want this. Your programmer will use this at ECU tuning (it's a perfect tool). After that it's not necessary. It's not a dragster car so save your money...
Exhaust: I have a 2.75" tube and it's perfect. 2" is a bit small. Low end torque will be ok.
AT last The Programmer: Make sure that he is a good one. Don't try to do it yourself! Always remember that the engines in most cases are blown up from bad tuning...
Cheers