> fast x86 cpu emulating
It'd be faster per Hz to emulate a PowerPC CPU via ARM, SPARC or MIPS CPU since with x86 you're having to cross endianness, and architecture so you're not only going to incur a performance hit, but power consumption and voltage requirements would likely be too high for an Amiga if it was x86. Heat is a consideration too. I'd personally vote MIPS since thats my favourite RISC architecture, but thats me.
Since there are some PowerPC chips being made ( Mostly SoCs ) it may be best to just get a cheap PowerPC with extended logic and libraries and plop that into an Amiga CPU slot. Using old Macs as donors, you could easily sell 68040/PowerPC cards for around the same price as the CSPPC goes, and I bet you they'd sell. I looked at 68060s, but according to Freescale's product page they ceased production and the last CPUs are EOL. Maybe someone has a Chinese supplier that can make them though. Making the boards in China may actually make it affordable.
I said x86 only because it's cheap, easy to get hold of and faster than anything else available at the same price point.
Regarding the endian issues, an x86 JIT emulating a 68k is currently faster than a PPC JIT emulating a 68k so it's not really a issue. See WinUAE vs E-UAE-JIT for OS4/MorphOS.
ARM would also be cheap and easy to get hold of but not as fast as x86 at the same price point. The power consumption would be the major selling point here.
