You might check with a couple of the OS/hardware vendors too. I know Microsoft used to have labs on both east and west coasts that allow you to do this type of debugging, I would imagine they still do.

Sun used to do the same thing back in the day, not sure since Oracle took over, but it would be worth a call. IBM/HP also might have a lab environment where you can test on.

Maybe call the machine vendor your client used for that machine and explain what you need, you'd be surprised how accommodating they can be. It won't be free, but it likely is far far cheaper than a 60 core machine.

Good luck!