Ok this is major thread revival.
There are factory kits that can be bought and installed. However I dont know if you would be able to find any for a car taht old now. Your best bet would be to call around to some local shops that install aftermarket systems. I know here in teh nashville area there is a company called Auto Air and Sound. They install aftermarket everything pretty much. Talk to some of your better custom shops to see if they know of anyone. the only other option is to buy the parts from teh junk yard off of a car taht has been wrecked. Then replace the dryer and some other parts also. Another thing to think about is pre 94 models used R-12 and after 94 most used R-134a. It is hard to find R012 nowadays and nrmally when you do it is pretty pricey.
try places like this
http://www.autoairplus.com/Toyota_Co..._1997-1993.htm
http://www.ackits.com/merchant2/merc...=AMA14411-2044
As for price I think teh kits from the dealer that we used to sell were around 600-800 dollars depending on the car and the labor was normally about 6-8 hours again depending on the car. We could normally have one done in about 3 hours or so. Most of the vehicles we installed them in though were Tercels and Truck/Tacomas.