Yikes!! $45 for shipping a cpu is a bit pricey, I'd expect him to wrap it pretty damn well for that.
I bought a full MC68060RC50 from amigakit around 2 months back - cost £50, but mask was 71E41J. It was advertised on the website as an XC68060RC50, but when it came it was the cooler running MC version - Amigakit wins another loyal customer!
Runs very nicely at 66MHz just with a fan - gets warm without the fan, but has never crashed on me even uncooled. Haven't yet got any thermal glue to put a heatsink on it. Runs very nicely on my BPPC since I replaced the 040.
As for the EC version I tried - ran most things perfectly well, but anything compiled for 060 was an instant crash - including Ibrowse060 and (iirc) PPaint.