Need advice on a decking material that’s compatible with shallow drainage valleys.

We’re building a third-floor addition to our historic row house.  The addition must be set back in order to be invisible from the street; so we plan to use the extra space for a deck.  Drainage is tricky since there are effectively walls on all sides.

My contractor wants to channel the water away from the walls and into shallow valleys, which then lead toward a corner drain.  Sounds prudent to me, but leaves us with the awkward question of what kind of decking material to use over a not-quite-level surface.

Anybody have any experience with the following options?  Or have other options?

We’ve considered HandyDeck tiles, which seem to be simple to install somewhat flexible.

We’ve considered Hanover pavers with a leveling system but are unsure if we love them and would also have to do some engineering to check the weight.

We’ve also considered building a deck out of Leisuredeck recycled plastic, which would have to be framed underneath to accomodate the various slopes, but I’ve heard different things about its reliability.

Any advice?