If my A/c clutch is going out does that mean my whole compressor needs to be replaced?

I have a 97 ford expedition my air comes out cool and then all of a sudden will come out hot. If the truck sits for awhile it will come out cold again for a little while, so its back and forth and a weird noise is coming from the compressor also. Can it be the compressor is going bad?

Yep, a new one costs about $600

Yes. If the clutch and/or barrings are failing in your A/C compressor the compressor itself will have to be replaced.