I am doing a little research into fax machines, I do know a little about them but not really into the mechanics of them. Which is better for faxing or receiving photographs? A thermal fax machine or a plain one? Is there much of a difference or are they just about the same?

Neither. Faxing is low res. Send photos as e-mail attatchments.

I have to agree with scott, the quallity is limited by the FAX-standards.
But if it is a requirement that FAX is the technology to be used I would recommend Laser or Ink(better laser) thermal usually fades faster.