I mean he power was so cool, that not before long we had a lot of cheap rip offs, like Reed and other heros.
Tsk, tsk, young padawan. Though Reed came after Plastic Man, Plastic Man wasn't the first stretching hero. That goes to Thin Man, a Timely/Atlas/Marvel property that predated Plastic Man by about a year.
A few Golden Age heroes would be cool, and it could be a period movie. Alan Scott as the original Green Lantern back in the 40's. Thin Man and his subdimensional Eden fending off Nazi's, the original Human Torch being created. Aarkus, a pan-dimensional police officer breaching the barrier to earth so he may hunt down a renegade superpowerful crook, etc.