There are Vista with SP2 disks out there. But you must be part of MSDN ot TechNET to get them. Only legit sources have the options to get them. They are not on illegal downloading sites.
I just checked my MSDN and sure enough:
Windows Vista with Service Pack 2 (x64) - DVD (English)
There is the ISO for Vista with SP2 for 64 Bit.
No. OEM disks are only supplied to the Manufacturers. There is no legal way to get them unless you are the manufacturer.
You maybe lucky if you have some good connections within some of the manufacturer's companies and get them to supply you with a disk. But other than that Microsoft isnt going to supply you the disk.
The ISO i showed above isnt OEM. It is Retail.