Try to sell the Efika and buy a key for your mini. The demand for Efikas is not the highest, but ...... It is a good base for projects like this: http://via.i-networx.de/eframe/eframe.htm
I was trying to sell my Efika, as I have had a 1.5GHz G4 MacMini running a registered copy of MorphOS2.4 for several months now, but since it has not sold I think I will copy that idea to make it into a picture frame media computer. I have an old 500MHz Celeron laptop that is literally falling to pieces (the hinges have broken the plastic laptop casing) that I could get a 14.1 inch LCD display from, if I can figure out the wiring to convert it to accept an input cable from the DVI port of the Efika's ATI 9250 video card. The picture frame project linked to above looks very nice and it is only a 10.3 inch LCD.
I think the picture frame project will be better and probably cooler without any fans if I use the 400MHz Efika running MorphOS2.4 than trying to keep and use the 500MHz Celeron laptop motherboard running Windows98, or some flavor of Linux.
@Hell Labs, I would agree with you that the Efika is very limited due to it's low amount of RAM capability, but it is hardly "totally useless". There are many things that the Efika can run and run well. Some smart programmer might even write an application that allows MorphOS to use a swap partition as virtual memory which while not a good solution, would make the Efika better at running web browsers that cache pages and/or images to RAM and cause the Efika to crash.