Bill's watches are VERY trick. Not to mention pretty reasonable for what you get. A note: he's on vacation for the month of September. PLUS he's coming out with a Benrus tribute watch soon. His work is very much worth recommending.
Don't know anything about Fortis really, just that its supposed to be a good swiss watch.
As for high end Seiko, it depends on what you're talking about. The 7s26 movement is proprietary to Seiko, whereas the myota movement in a lot of Citizen autos is sold to a lot of other companies (I believe the low-end Invicta watches have the Myota). I like the 7s26 just for the proprietary aspect. Although, I think the spring-drive seikos are nice as well- if a bit pricey. As for the REAL high-end Seikos (Credor, and King Seiko), I don't think Citizen really makes anything in that class.
Oh, the Tissot Seastar is a nice watch for an auto as well.
Just my .02, and worth what you paid for it.
Oh, and the next watch I plan to buy is the Orsa Sea Angler. Anyhoo, lots of great watches for your price range, good luck with the decision and let us know what you get.
Sincerely,
Anthony