Dead compressor - what else should I check/change?

A year or two ago my A/C started getting pretty poor. I recharged it a few times over a couple of years and it got better for a while, but for a long time it would only work while driving and not while stopped.

My compressor finally completely died so I bought a new one. I'm going to install it soon. I have a receiver/drier on the way as well.

Are there any other parts I should check or replace while I have the system evacuated? What about the thermal expansion valve? It's almost $50, is that something I should just replace or is it easier to hold off until I know I need a new one?

$50 on the valve that would be up to you. The only other real thing I would look for is any visual notification of corrosion or any other telltale sign of something being wrong with the system. Do a visual inspection for anything that would look out of place.

Have the system cleaned out and see what happens.