For my dollar I think you can't beat Freestyle's Arista EDU ultra is comes in a variety of formats and a good selection of speeds in 4x5. They also carry efke, ilford and kodak. Their customer service cannot be beat by anyone.
X-ray film is cheap but bear in mind it is usually a double sided emulsion, unless you get mammo film, and it is blue/green sensitive(orthochromatic) and is all quite slow. The double sided emulsion will eat up your chemistry faster. The single emulsion is better for speed and contrast but is usually only available in metric sizes. I use single emulsion mammo film either kodak min-r or fuji ADM for making enlarged negatives.