what's your transmission in that land cruiser? is it an automatic? do you have a separate tranny cooler, or is it integrated into the main radiator? I separated the two (they were hot like a couple of fighting toddlers, I tell you) and I saw drastic improvements in temperature.
Also, what kind of shrouding do you have around the fan?
Sorry I didn't read all of your post...
I think that fan you linked to is going to be too small for your application. I'm running a Flexalite FLX-295 (4600 cfm) and I'm running a high performance small block. It's a scirocco-style fan with built in shrouding, and it's a puller. Look into a dual-fan setup with proper shrouding and you will see a drastic improvement.
Hope this helps