Went to the home center today and picked up an exhaust fan and a laundry sink. There is a basement window in a convenient location that I can block off with a section of plywood to hold the vents. I'll probably end up running two fans. I also have a blower from a De-humidifier that I am going to modify to provide filtered air into the darkroom area.
Things are slowly coming together, I'm trying to do things (mostly) right the first time. Should be hauling home an ancient Omega D-II in a week or so to handle the 4X5 work.