Pitch pine; European Oak; Iroko; Teak.

Iroko is a dense heavy hardwood, far more so than Oak.
The downside of Iroko is that if recut will twist from varying
internal stresses.

Steel UB/RSJ zinc-epoxy 2pk coated with slipped in Iroko planks?
Alternative to hardwood planks is wood-fibre-in-resin rot-proof planks?