I had a lot of trouble runing 64 bit VMs on with Workstation 7 installed Server 2008 R2 some time ago. Initially I bought a 1st Gen Core i5. Then I found out I needed both a CPU and Motherbaord/Chipset that supported Intel VT-d to run 64bit VMs. A New CPU and carefully selected motherboard later all was fine!
I'm now running workstation 8 and looking to upgrade my host machines and landed on this thread looking for info on VT-x/EPT.
Now Intel do have a couple of helpful pages the first being this one where you can search for CPUs that are support features for virtualisation including VT-x, VT-d and EPT. http://ark.intel.com/search/advanced/?s=t
There's also a page on Intel Motehrbaords listing INTEL Desktop motherbaords/Chipsets that are compatible with VT and VT-d.
http://www.intel.com/support/motherboards/desktop/sb/CS-030922.htm
I can't seem to find anything similar for VT-x/EPT. This may now be included under the Intel "VT" umbrella.... but I'm not sure. But my tip for folks is the CPU feature support is only part of the puzzle. Both your Chipset AND BIOS needs to support the Intel virtualisation features and it can be very tricky trying to find out before you buy!