I have no knowledge base on which to make an informed decision. The reason I want to try this, though, is to test the idea that proper sizing of the transformer and proper choice of materials should give the lowest zero crossing distortion, and maybe better low level quality. A bit more delicate, if you will. I'd go with your recommendation here. If you see the speakers, and given the time spent already, you'll guess that moderate cost differences are not a major issue (excluding platinum laminations and gold wire with rare silk insulation - type of thing).
Sheldon