Does anybody know if all the 1987 Suzuki Samurais came with air conditioning
from factory?

It was an option, but not standard.  They convert well into on-board air. 

How can you tell if it came with it

Should have a A/c compressor, condensor,A/c switch on the heater control panel. Blue button lower left side of panel.

Yea mine doesn't have any of that, how hard is it to retro fit one in

How can you tell if it came with it

It will have a dual row vbelt crank pulley.

Yea mine doesn't have any of that, how hard is it to retro fit one in

Not hard, just find a donor with all the pieces needed and put it in.  You'll find it more in tintops than soft tops.

i have a heater control with A/c and the comptuer for it and the condenster in the heater box just need pump and lines 100 bucks

It was an option, but not standard.  They convert well into on-board air. 

Have you done that conversion? or seen a build of it online?

Google will find you several articles on the conversion - including Samurai specific ones - just search for on board air.

Here's one from iZook.