I'd say the hardest part would be to get that PBT ISO enter key. The other keys wouldn't be too difficult, I imagine. Maybe someone knows something I don't, but I haven't seen that many ISO PBT kits available thus far.
I think your best bet might be to order from WASDkeyboards, as they will soon have PBT options available. A full set shouldn't be that expensive, and you will likely be able to get them blank or etched/engraved.
Other than the ISO key, you can get a normal ANSI kit, and most of the keys will work, you'll just have to worry about that extra key, the pipe, shift, etc. But the most used keys would work. Blank PBT kits aren't that expensive, and it could tide you over until a clear best option (like WASDkeyboards kit, if it is complete) is available.