None of the components, other than the TV, know the difference between analog or digital signals.
The old antenna and flat twin lead will work as well as anything thing new, if they are intact.
If the insulation on the twin lead has broken down, I would replace it with coax. Use RG-59 to be specific. This is the industry standard and available at any Radio Shack.
Use an adapter like this one to convert the coax to the flat lead connector on the antenna, or to convert the flat lead to coax at the new TV.
Outdoor antenna matching transformer balun 75/300 ohm TV F cable adapter | eBay