We can't turn off HT on VDSes, I'm sorry. It's fundamental to the way the system works.
To run a 64-slot server, you'll need to be on one of our fastest machines -- an E3-1270 or X5675+ one, most likely. If you're not on such a machine now, contact us, and we can check for availability.
do I just use a General Inquiry ticket? I love NFO.