No there is NO gains from exchanging the SP1 for a SP2, If you go to ebay(just for reference of pictures)
The SP1 has a mounting bracket across the top and mounts up front-between the radiators..
The SP2 mounts vertical, lower front, near the bottom.
As far as answering your question completely.. I don't know of any aftermarket oil collers that would be any more efficient than the factory cooler...