I don't think there is much difference between alum and copper. However the copper mfgs I know about are all oldtime manufacturers selling a proven product (if new) as apposed to those that make the alum. The important issue to me would be the quality of the construction of the alum rad not should I get, alum or copper.
As I didn't know the quality of any of the alum mfgs I picked copper and bought from an old line rad mfg in Memphis, Walker Rads.
