Good concept, I like it. I would've gone with one large heatercore instead of several smaller ones run together. For example, the core I use is a 9"x9"x2", I got it from autozone for roughly the same price you got two of your rads for in your previous post. Here's a picture:
The fan is a 172mm Comair Rotron Patriot, 24v, just to give you an idea of scale. Note the built in mounting flange.
--HP