All CPUs on all boards will be socketed. Didn't you see the picture of the custom-made PGA sockets yesterday?
However, removal of the original CPU voids warranty. We cannot be held responsible for anything else than the factory configuration. If you decide to put your own chip on the card, you're on your own. The only user option(s) are the jumpers. If you want to keep your warranty, the CPU is off limits. Besides, the ACA630 comes with an MMU (did anyone care to read the product description?).
Zetr0, as described in the text on www.icomp.de
(which is a lot shorter than this thread), the SD-Ram controller is clocked twice as fast as the CPU, that's why we need a 50MHz crystal on the board. I'm serious about not overclocking, as the 50MHz give precisely the timing that the memory chips can handle: 20ns from row-open to column access, and also 20ns from precharge to row-open. The CPU may not fail at higher speeds, but the memory will.