A couple other options for the radiator:
![Image](http://www.griffinrad.com/images/rad_images/large/OR-00038.png)
That one's a little wider and would require custom mounts, but has two waterproof electric fans. The off-road versions have deeper fans as well as performance curved blades which pull more air for that high heat/low rpm stuff we like to do. Runs about $600.
Here's a cheaper version on ebay with an integrated electric 16" fan. Doubt it's waterproof.
Of course, if I'm going to think about an engine swap, I'll have to take into consideration the inlets/outlets of the new motor.