you can, but its hard.
no, its not, unless you have an unlimited budget. people have done it on SSFTC's and unichips. emanage works like junk on the MSP.
for 250whp, you need a 2.5" exhaust all the way back, FMIC, unichip, exhaust mani, 440cc injectors (i think), intake mani would help, EBC, boost gauge, wideband, and a wicked tune. a larger turbo would help considerably, as the GT25 is out of its efficiency range at redline above OEM boost. thats not to say its a bad turbo, its adequate, but youll make more whp on a bigger turbo at the same boost - plain and simple.
all of the above would probably make 250whp @10psi on a GT28rs, assuming you have a good tune, and the knowledge that youre pushing engine limits at 250whp.
sometimes ur answeres seem ignorant to me. how do u figure that the haltech is not worth the extra money over the unichip. i promise the tuning cababilities over the unichip and the hatech are a huge difference and seeing as unichips brand new are only 100 dollars shy of getting the sprint 500 hatech wich is a perfect tuning unit for any protege and at that price its well worth it. if u plan on big power like that u might aswell get the haltech seeing as u can tune it urself along with every other good tuning shop around.