#2
The only thing you would have to do would be to drill holes for the pivots posts. But nothing too extensive, no other routing I believe.
#4
I am not sure about that. Reason being those may take a large bit to drill the post holes, one that could require a drill with a 1/2" chuck. While the chuck on it's own isn't too much money, a drill that makes the power to drive it often is. Make sure the pivot post holes don't take larger than a 3/8ths" bit
#6
That is a cheaper version. Note the slightly thinner baseplate and lack of a Wilkinson stamp. Likely made in China too.