Compressor replacement
 

I just picked up my '95 XJS 2+2 4.0 liter on Feb 29th just ahead of all this Covid stuff. It is a beautiful well taken care of car with 76,214 miles on it now. The last owner had it for 21 years and only put 40k miles on it. He tells me that the A/C was working fine last year but I had it serviced because it just didn't blow cold. The technician told me that I need a new compressor.and I could really use some help with which replacement to get and whether I need anything else besides a new dryer. I am not sure which model it has in it other than it has a single v-belt pulley' I of course don't want to get one from the dealer because of their prices. If anyone out their could point me in the right direction with a replacement suggestion I would greatly appreciate it. The weather here in southern MS is just too hot to go without A/C. I hope I am posting this correctly I just have not really done much but read from the forums. Anyway thank you in advance for your feedback.

I use Rockauto.com, they have much better prices that the parts stores.

I believe the compressor is a Sanden SD709, call around to various AC places and you should be able to find one. They are used on many vehicles, so your rear housing may need to be swapped over and possibly the clutch.

If your system is holding pressure, then I would add replacing the expansion valve to your list. If you're experiencing leaks, the three more common points of failure are the condenser coil, also purchased at Rock Auto (and straightforward to install), and the two schrader valves, which are easily replaceable and inexpensive. I believe the two valves are easily sourced at local common auto parts store. They just unscrew!

I ordered the kit with the SD709 compressor, accumulator dryer, and the expansion valve. My guy will probably have it done by Monday. Thank you for your help.

Air Conditioning leak fixed - cut off switch
 

I had problems with my air conditioning for years - it would be filled, work well, and then a few weeks later not working again. After having it filled a few times and complaining, finally a mechanic told me the cutoff switch was leaking. Once that was replaced it worked fine ever since.
The part was A/C Compressor Low Pressure Cut Off Switch (JLM1260). I forget the cost but it was not high.
I dont know why it took a few mechanics and lots of time to discover this issue.