With only 500 pieces worldwide, this luxury wristwatch goes to a good cause and is made for the super-fan.
I've got one, it's nice and functional. The quality is fine for what it costs here, I think it was around £125?
But $300 seems excessive and possibly not worth it?.
Seiko Prospex (SNE585P1)
It's a 38mm solar quartz diver around 10mm thickness and has 20mm lugs.
Seems to fit most of your requirements. I'm contemplating it myself.
This account is verified. WatchCrunch has confirmed that this account is the authentic presence for this person or brand.