I'm thinking the only type of "plastic" safe to use would be like an ABS resin mold plastic and that's not end user shape-able.
PVC style plastic gives off fumes when it gets past a certain temperature. Not a viable option.
The tubular steel design would work great, just the time involved in designing & fabricaing such a piece would be temendous. PER PIECE... Still would be worth it IMO though!
