One thing that could keep the spindle from fitting is the connection to the strut. That is really my only concern as it looks like the ball joint of of the same design.
For brakes, you can either go with rav4 brakes, which would likely not be any improvement over 185 brakes or you go custom. Custom would be easier since a supra rotor would bolt on, then it would be a matter of just choosing your calipers and getting a bracket made. Ksport makes a BBK for the rav4, but its well over a grand. It may be possible to use the revolution BBK from the celica since it 1) used supra rotors and 2) the mounting points on the caliper are the same. We do not currently know the offset though of mounting ears.
I may have a spindle on the way soon, so I will keep you all posted.