That looks pretty nice. I've done a couple sets of dining chairs. The first I just added a layer of 1/2 close-cell foam under the existing pad, and new chenille fabric. Looks very nice, and better than they were as far as comfort.

The second set I bought without any seats at all, and had to make a seat template from scratch. For the cushioning I had a couch that was going to the dump, but had pretty decent 6" thick foam cushions. I cut them in half to make 3" thick chair pads, which wound up being perfect; not too thick, but almost luxuriously comfortable. That sort of thing isn't as hard as people think, and is pretty rewarding.