Thanks. Yes I don't plan to use pavers for the reason you state. I actually found this company whose link you posted after making the OP. Using them is definitely an option, but even their "in stock" items seemed more costly than having it done by a local welder. Composite deck boards may be the way to go. Just need to get the right spacing on the supports. Was thinking maybe I could just notch the blocks, add steel cross beams and lay the decking over that.
If that is the case I would run the deck boards in the short direction. I would use three supports. It looks like you have 36" from the edge to your tub. Most composite decking is a 16" maximum span. If you make the steel supports wide enough, the clear spans would be less than 16".
You could attach the decking material together in 2 or 3 foot sections, that way they are stable, yet light enough to remove easily. Making the beams removable is a good idea if you every have to take the hot tub out again.
Just as an FYI, I am putting a ground level deck/walkway around a quarter of my tub (over the existing pavers). I looked into teak - $$$$$$, then I looked into clear redwood - $$$$. I'll be using composite decking.