For anyone interested - I changed out the heater valve today and it wasn't a bad job at all. I unplugged the speed and reference and oxygen sensors and removed the bracket. I moved the vacuum hoses and brake booster hose out of the way as well.
Once you do that, access is pretty good. The job only took me 2 or 3 hours.
Now that I've addressed my coolant leak, I can move on to my oil leaks....
