@Mikej
Why instead of supplying the expansion board with a built-in 68060, you just sell it in two variants, a cheaper one without 68060, only with its socket.
Another recommendation, is that you enable 5 volts on the cpu socket by changing a jumper, so that you may even use a 68040 and you may avoid 060 shortage or even allow price reduction this way (68040 are way cheaper).
PS: 68EC060 cpus are much more easily overclockable than their counterparts. A fact of life of the 68k line cpus is that the FPU is the less tolerant component to overclock, so if you get rid of it, you can go higher mhz.
