This is a real game changer: http://qrp-labs.com/qcx.html
I've managed to convince a few VK stations to build 30m versions of this kit!
Please keep in mind the following additional useful information:
Excellent construction and technical information manual is here (PDF).
Reduce current drain on RX from 140mA or so:
The backlight is connected to the + supply (nominally 12V, recommended range 7 to 16V) via a 270-ohm resistor. There would be nothing to stop you from cutting one of the wires of that resistor and taking a couple of wires to a switch, to control the backlight. Note that the BLUE backlight LEDs are a little harder to read with no backlight, than the yellow/green colour ones. Of course the module used in the QCX is the same as the Ultimate3S one http://qrp-labs.com/ultimate3/u3s - although it is a high quality module custom-manufactured to order for QRP Labs (Not the cheap eBay kind which have only a single backlight LED), it does have the same "industry standard" 80 x 36mm PCB and 16-pin connection pads. And the same HD44780-compatible controller chip. So you can substitute any other 16 x 02 LCD module if you wish, too.
"Switching" the backlight should be easy with an external switch. Options might be to open the backlight lead completely, add resistance to lower light intensity and reduce current draw, or add a push-button (momentary ON) to view the LCD with backlight only when desired
Modern LEDs as used in today's LCD displays will provide fairly bright illumination at currents of 3 to 10 ma. Try using a larger resistance value in series with the backlight LED. Usually 1K in series with a 5V or 2.2K with 12 volt source is adequate for both day and night viewing. Experiment to see what is best for your particular situation
Dual Band Operation
You won't be able to use the band pass filter T1 on either band. It is single band because it is quite sharp (see spectrum analyser traces in the manual). You could probably find a number of turns for the tuned winding of T1, which allowed the trimmer capacitor to tune for either 20m or 30m. Measured tuning ranges are also published in the manual. BUT, it would mean that when you want to change band, you would need to re-peak the BPF each time using the self-alignment menu item "8.7 Peak BPF".
You could build the LPF for 20m and operate 30m into it but you may not achieve adequate harmonic suppression on 30m band.
The Class-E resonant circuit is quite broad and you could find a compromise-value, it would probably result in a little loss of efficiency and power, but may be acceptable.
Another option would be to have a separate board with switched circuits for these three blocks (LPF, BPF, Class-E).
If you want to widen the filter for reception of SSB (on other bands):
The 200Hz filter is quite sharp (see the measurements in the back of the manual). You would need to bypass it. The receiver has quite a lot of available gain so the loss of 18dB may not worry you too much. But you might want to consider building a separate LPF with say 3kHz cut-off and a gain stage, and making them switchable.