> Instead of a skillet I bought a cheap electric cooking plate and put > an aluminium plate on top.
That's what I've got too. No temperature control, though - the warm-up curve is good enough for me as-is. I ∗do∗ have to let it cool down between boards, though. I put the board on it when it's cold, turn it on, and six minutes later everything reflows and I slide the board off.