I voted for an FPGA solution.
The answer depends on what you consider a modern 'Amiga' system. To me, a modern Amiga would be something running a patched OS 3.9 with 68k programs on 2012 hardware.
Much as I love the original classic hardware (even more with modern hardware expansions), my old 1200 will not last forever so I'll need an FPGA system to replace it.