those nissan turbos are garrett made (private labeled)....just liek precision turbo or inovative turbo...or the alike, all get their parts from garrett.
the rb25 turbos are just like those garrett's t28...all same the sh-t...send the turbo to Majsetic Turbo and they will rebuild for you. they have fast turn-around-time
http://www.dallasturbo.com tehy rebuild all make and models.
i would just add a few more $ and get a bigger aftermarket turbo...but that's just me.