I did a little searching and there is info out there. With that said, the general concensus is regardless of which aluminum radiator you use, hoses will most likely have to be custom. I don't know what others did, but what worked best for me was using the blue silicone elbows with aluminum tubing. It's not the cheapest way to go, but the most convienient and best looking IMHO. You can get the elbow from Pegasus or Racer Parts Wholesale, and I'm sure other places.
I have the Arizona Zcar radiator which from what I hear is a Ron Davis unit. It's very nice, I NEVER have any overheating issues on the track, and this is with a very healthy L28. This requires custom hoses as well. The outlets on are 1.5" and the ones on the motor are 1 3/8". I used 1 3/8" silicone hoses which easily stretched over the 1.5" pipe and fit nicely on the engine side.
There's a few engine bay pics in my zdriver gallery if you're interested:
http://zdriver.com/gallery/showgallery.php?cat=500&ppuser=3088