Brake upgrade to 93+ system

I have a 90 sw20 and I would like to improve both the feel and performance of my brakes.
My understanding is that from 93 on, Toyota went with bigger brakes (discs) and hence the change from 14 inch to 15 inch rims? I’m now running 17 inch rims
I’m thinking 93+ calipers on front and back, with new (slotted maybe) rotors.  The calipers should just bolt straight on shouldn’t they? (one of the reason I’m thinking about going this way)  Anyone have any thought comments or want to highlight flaws in my thinking.  I just have to source some 93 + calipers then. 
 
 
thanks
Dave

Best to update the whole system booster, master cyl etc. Dont forget a vacuum check valve. Best to source a generic 1 from the wreckers as the later check valve is in a hard line in the engine compartment.
If you do upgrade I will have a full set of slotted rotors available soon.
 

Moefan 
Is your car an NA?
IMO, for a car that is mostly driven on the street if the early model small brakes are well maintained they should be totally adequate, even with plain rotors and stock Toyota pads.
However the pedal feel can be greatly improved  by fitting a one inch M/C and a '94+ booster + check valve. 
A M/C brace also helps.
I run that setup that gives a much firmer pedal with a lot less travel, but still only needs light pedal pressure to stop.
 
BTW, if replacing a M/C I would recommend forget the wreckers and get a brand new one - they are a vital part.
 
 

Thanks for the replies. It is a N/A model.  Sounds like a need a few extra bits to go with the calipers and rotors