ALL alarm clocks should run in 24-hour mode (not AM/PM mode). Normally 24-hour mode isn't practical. HOWEVER, on alarm clocks, it prevents you from setting the clock 12 hours off (if you're setting it while falling asleep). (products that are capable of this include: Sonic Alert SB200ss, ...)

My alarm clock setup:

• Hard-of-hearing alarm clocks
  Specifically 1x Sonic Alert's SB300ss and 2x SB200ss, all with adjustable volume and bed-shaker. (9v battery backup, acquired for $35 ea)
• X-10 alarm clock
  Specifically the XPMT1 (2xAA battery backup, acquired for $35). Designed to work ALONGSIDE the Sonic-Alert (the X-10 isn't loud, doesn't shake bed, and the two have separate clock settings). Turns on many lights at the desired time. Can turn on my 1amp fan.
• X-10 Powerflash
  Since the X-10 alarm clock is far too complicated, this is triggered by the 12v signal that goes from a Sonic Alert to its bed-shaker, and it sends an "all lights on" X10 signal.

• buy an aquarium pump, figure out how to get it to "spray" more like a squirt gun
• possibly buy the X-10 110dB siren (though the Sonic Alert alarms are claimed to be 113dB)