Look into basses with filter-based electronics. If you can afford one, Wal's are the holy grail but there are plenty of other choices out there. Aria Pro II SB1000, Alembic, Heartfield, any Ibanez with the vari-mid circuit, etc.
You can also get interesting results with your set up. Nice bottomy set of strings and low action, almost bottoming out.
But per the OPs post, Warwick is a great choice. I would go with a Masterman, or FNA (original or Jazzman). Stingray killers!
I also love the Ibanez ATK. Sickest bass you will ever find for the price and the best thing Ibanez ever made IMO. There is a nice ATK205 in the 'fieds now for $300 for example.
Good luck!