looking for a clean low mileage 85 but have some concerns
 

My very first new car was an 85 Supra P type. I loved that car and now I'm thinking that I'd like another one to use as a daily driver. I only kept my 85 for 2 years before trading it in on an 87 Supra turbo so I really don't know how reliable it would have been. I probably only had 25000 miles on it when I traded it in. My concerns are this: Most of the ads that I see are for cars where the A/C isn't working. Is this a common problem? If so are they difficult/expensive to fix and become reliable? I live in FL and A/C is a must.
This brings me to my next concern...Are parts readily available from dealers or aftermarket suppliers? I'm sure that interior and exterior trim pieces are probably out of the question, but are the mechanical pieces available?

almost every mk3 turbo supra blew its head gasket around 200'000k
but your 85 is probly still going.
as far as air conditioning goes, its an old system and probly needs to be switched to the new gas type. it can be done, and people do it all the time. do some research over at www.celicasupra.com you will find all the parts you need there and all the info. if you need any help finding parts let me know.