A warning about the HS-TWS, turns out the web page dimensions have a typo, the fin height is 29/32" not 2-9/32". My rough calculations give about 2.5 °C/W, should still be plenty for 15W, so I think I'll keep them without complaint.
I snapped a photo
to give a sense of the size, the heat sink is just over 4-1/2" wide.
For thermal compound, ordered some paraffin based phase-change interface material, kinda pricey at $17, but I can't stand using that other goopy stuff either. Digi-Key part HS243-ND.
For the PS, I've made a few further refinements (adding pre-regs, a couple more caps, and opamp protection diodes) to Kevin's tracking version of the Didden-Jung circuit, from my previous post
on the subject. Should have all the parts soon if I can remember to order the transformer tomorrow
I can draw up a new schematic when I get the chance if anyone is interested (PM me rather than cluttering up this thread).