If you can find anything for a four door then yes the Impala parts will interchange with a Biscayne, or Bel Air, or Caprice. All of these cars are the same, the different models were distinguished by the level of the trim. The interior added things such as a set of small arm rests up front then modified the small arm rest to a longer more comfy arm rest before adding arm rests in the back with added trim and finally adding carpet to the bottom of the door panels to prevent scuffing.
Chrome doesn't make a car go faster or handle better but people are willing to pay more for a Cadillac than a Chevy even though they are the same car today (after 1972 GM put Chevy motors in the Caddy instead of the expected large cube slow reving torque monster that characterized a Caddy engine).
By the way GM made five models of the same car Chevy Pontiac Olds Buick and Cadillac. They were basically the same car (the big Caddy sedans are actually eight inches longer in the back seat area so that won't work for door panels). Otherwise the only difference is in the trim. I installed a full Buick Electra 225 interior inside my 1985 Impala when I got tired at looking at the greasy torn cloth interior. I enjoyed a much more comfortable split bench powered seat with a built in arm rest, much better stereo radio (didn't install the power antenna) pulse wipers and cruise control all attached to a tilt steering column converting my cheapo taxi into a much nicer car. The Buick had a lot more added sound deadener and thermal barrier under the rugs which where also nicer than my Cheapo Chevy rugs after 189,000 miles. I accomplished all of this by buying a dead Buick out of my neighbors yard and stripping it before hauling what remained off to the bone yard.
Because a four door isn't as popular as a two door few companies offer anything for your car except parts that fit both two door and four door cars (such as floor mats). Of course mixing and matching interiors, motors suspension or other parts upsets a lot of purists that think these cars must be preserved exactly as they were made and not driven.