I would get 2x8GB 1066 SODIMMS and replace everything in there. That will give you the best compatibility.
You don't need a cable for the hard drive and while it's nice to have a caddy you won't really need that either. The SSD will just slide into place and you can either add some spacers to keep it in place or some velcro. While you can get a caddy it's just easier to rig your own mount, IMO. I'm just using some cardboard as spacers.
😛Not sure about the wireless. I know people have changed out the modules on several of the models so you might just want to search here on the forums.
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