405 heads are cheap and easy enough in this country, that they should be put onto everything as a matter of course...
The 531 head is better, but not worth the extra money IMHO.
I'm a big fan of the K cam for road cars. Also cheap and easy to obtain in Australia.
The H cam is better, but is also more expensive, and has a lumpier idle and somewhat weaker bottom end/lower midrange, and uses more fuel. I find it difficult to get excited by the H, but seem to be in the minority there...
So yes: 405/K is a good option.
There's a lot more than $102 in labour to reco any cylinder head - Joe roughly paid for a second hand head and got the reco for free.
Prices are highly variable, but I would say that a good used 405 and good used K should be under $200 all up. If I have spares of both, I'd be happy to part with them for $150ish (depending on exact condition).