Chappy

Ummm...I fail to see the problem here...
Nod32 for 64bit Vista shows as ekrn.exe *32 in the Process list but that does not mean it's any less effective on a 64bit system. Nod 32 is widely considered by security experts as top-o-the heap for AV products and I've worked as an Independant Malware tester for major AV products for over 8 years until 2004.

Still, the fact that the av resident kernel mode is acting as a 32bit process does nothing to inhibit your protection, so basically just go with whatever AV product you wish that offers a 64bit version. In most cases (probably all in fact) you'll find that it's only the AV's GUI that is actually running as a 64bit process and the kernel mode is 32bit.