The Perfect PDA/Calculator

My current Palm Pilot Professional (very old) measures 4.7 x 3.2 x 0.7 inches with a 2.2 x 2.2 inch (160 x 160 pixel) backlit screen and weighs 5.7 ounces including two AAA batteries. The case size and weight are perfect and the PDA described here should not exceed these measurements.

The thickness of each half is not drawn correctly in the picture but the total thickness of both halves should not exceed 0.7 inches.

Here are some of the features the PDA should have:

Primary 2.2 x 3.0 inch (240 x 330 pixel) backlit color or grayscale touchscreen.
Slide out grafitti pad extends height by 0.9 inches.
Secondary 2.2 x 3.6 inch (160 x 260 pixel) backlit monochrome touchscreen. This screen is powered on and off by software. The main purpose of this screen is to display a touch keyboard but could be used for anything. The backlight is linked to the backlight on the primary screen.
A sturdy high-quality case similar to the HP48gx calculator.
Wireless (IR and/or radio) and USB.
Dual expansion slots, one in each end of the secondary screen. There should also be a memory slot for standard memory sticks even if it means giving up an expansion slot.
Direction pad, grafitti pad and primary screen are software rotated when secondary screen is in landscape mode (keyboard uses this mode). Other applications of the secondary screen could use landscape or portrait mode.
The processor should be atleast four times faster than the 16MHz DragonBall in my Pilot. I only use it to read text and this PDA will have four times the pixels so its clock should also be four times faster. :)
About 16MB of storage.
Long battery life.
Decent audio hardware.

Some software:

It needs to be powered by the perfect operating system (BRiX)
A calculator program with all the features of the HP48gx to replace mine.
A text editor/viewer that is better than my Pilot's memopad. Mine doesn't remember the current page for each memo so it's not possible to hop back and forth between memos.
An mp3/ogg player, would require additional memory.