I've been trying to find vendors for the better AL & CU alloys in bar stock.
Aluminum in 1199-H18 (240 W/m-K) or 1199-O (243 W/m-K)
and
Copper in the Oxygen-free high conductivity types, C102 ,etc... 391-392 W/m-K
Searching now, but if anyone already knows any, it would help