MWR does NOT "make" valves and springs. they simply retail them.
Pioneer makes the springs.
eibach also makes springs for the celica along with crower who does GT only for now. they dont expect to start on the 2zz til the later part of this year.
I have been very impressed with what I've seen from the ones mwr sells. I would reccomend it.
I also have a set
they just arent in yet.