Something that's still available and will do everything you want with proper software and library support and 50 mS wakeup time:

[Link: commandsystems.com.au]

I've had 2 of these at home for about 5 years now, both with the same programming but the ability to choose between bedroom or lounge room setups. They use 4 x AA alkalines - I use AAs that no longer work in my digital camera and I get about 3 months from a set.

The colour LCD is backlit but it's only 8 colours. Despite this it still looks good, doesn't pull lots of power and doesn't need a docking station to charge it.

The software's WYSIWYG and quite intuitive - you can make it do pretty much what you want with nested menus etc. but it can take a lot of mouse clicks because it doesn't make any assumptions about how you want it to work.