Oddly enough 300 ohm twinlead under ideal conditions may have less loss than coax. There is also another option called shielded twinlead. Whatever you get make sure you get good quality cable and connectors. The few dollars you save here are going to cause you lots of grief in the long run especially if you get cheap connectors. Below is a chart of attenuation for coax downlead.
Inexpensive cable can easily be much worse.
It has a short piece of twinlead on one end and a standard coax connector on the other. If you are not using a preamp then that is all you need. If you are using a mast mounted preamp some of them have a 300 ohm input and a 75 ohm output. This eliminates the need for the transformer at the antenna. You might save it to use on a television that doesn't have a 75 ohm connector.