You may want to try searching next time (I actually had the same question as well):

https://www.honda-acura.net/forums/s...arket+radiator

https://www.honda-acura.net/forums/s...arket+radiator

https://www.honda-acura.net/forums/s...arket+radiator

And from H-T:

http://www.honda-tech.com/zerothread?id=219217

The prime choice here seems to be the PWR -> $300, which is still steep but under your price cap.

Shingo