Re: WSM build on long action???
If I was going to build a 9lb rifle on a long action, I'd choose the 7mm Rem Mag from the 4 you listed.
You could build the Edge at 10lb's but it would be a handful, even with a brake. It would be manageable if you don't mind recoil though.
If some is good and more is better, then too much is just right.
My mind is a raging torrent, flooded with rivulets of thought, cascading into a waterfall of creative alternatives