The delphi compressor comes with the 2 o-rings that you need to attach the line set to the compressor.
The AC delco drier comes with o-rings as well
the orifice tube I bought from advance auto parts and used a code Paid $4.
If your car is a 99 or newer , the orifice tube has a weird crushed plastic end. The new versions sold at the part stores use an actual screen now.
I also picked up a bottle of PAG 150 oil.
You will want to want to empty your compressor oil and the compressor oil in the new unit into 2 measuring cups.
then follow the instructions included with the new compressor. It will tell you how much to add back into the new compressor.