Make sure that the machine shop pressure tests the head. They will corrode between water jacket and combustion chamber.
I've been there, done that with getting oil and water out. I simply went to Wal Mart and got cheap oil filters, about three of them along with a few cases of cheap 30W oil. Upon reassembling the engine I put on a filter and filled with the cheap oil. I started the engine and ran it about five minutes and changed the oil and filter. I then started it and drove it about 10 miles to heat up the oil then changed oil and filter again. I then drove it to work and back (a 178 mile round trip,) and then drained oil overnight and put in my regular filter and oil. That was about 80,000 miles ago and all's well now.