Others have mentioned a few locations, South Florida is a big one with the wreck diving, as are Grand Cayman and Cozumel.
One thing you need to understand though is many operators are not accommodating to "tek divers" in some of these destinations, and if you walk into some random operator in a place like Grand Cayman or Cozumel and ask about doing deep or deco dives, they may look at you like you're an alien from another planet. Or worse, you may get thrown off their boat for "bad behavior" (I'm guilty of that one, in Cozumel, myself).
At the very least you need to talk to the operator before you get on their boat to let them know what you want to do and make sure they understand your training and background. Operators that have no / minimal technical diving background do not really understand what we're about, last week I had a divemaster in Ambergris Caye tell me that people cannot possibly survive decompression diving for long, then I showed him my computer dive log (my previous dive was 200 minutes at 100', 5 hours total run-time).
So here's Ken's quick list of dive operators that will let you do these dives in some locations.
This list is just some operators that I have used in the past, and allow technical diving. I encourage others to add to this list.
Florida Keys - Florida Keys Dive Center and Rainbow Reef should be able to hook you up. Talk to them first when booking the charter. There may be others, but those are the two I know.
Pompano / Ft. Lauderdale, FL - Odyssey Charters (in Pompano Dive Center). There should be others here too.
Jupiter Florida - Jupiter Dive Center
Grand Cayman - In-Depth Watersports and Divetech (other operators will look at you like you're an alien)
Cozumel - Rolly @ Dive Cozumel (but when I talked to him about a year ago he mentioned he may be relocating) and Deep Exposure. Other operators will likely throw you off their boat.
Belize - Belize Diving Services in Caye Caulker. Amigos del Mar in Ambergris Caye.
Bahamas - Bahamas Underground (Abacos, and focuses on cave diving not boat charters, and I haven't dove with him, but Brian should be able to help steer you in the right direction).