best kind of cooling for basement...

a res on the cool floor, or a bong, or just a rad???

ambient is 70-72°f all the time, no matter what ( cooler in the winter, but were talking summer now )... and around 70-73% humidity ( got me a hygro-thermometer ).

just looking for the best setup for this environment... TIA

I would say a rad, with two fans, one pushing and one pulling. Basement=cold air, coldair=good for rad.

Bong efficiency probably won't be great since you are starting with fairly humid conditions. A bong will add even more moisture into the environment, lessening it's efficiency even further. I'd go with the traditional heater core, as it's easier to build and maintain.