What's the big rush?
I don't know much about the 3M line, but both Meguires and Menzerna make top notch stuff. If you had everything planned out, sort things out with the place you bought the supplies from and do it right the first time. Your plan looks pretty good though.
Meg's 105 might be too aggressive but it's really tough to know without seeing the car (or at least some pictures). You have to assume the car has never been professionally detailed. A two year old car (especially in Black Sapphire) might need it. Maybe you can take a few pictures for us?
And I would wait 24-48 hours after applying your Klasse SG before applying a wax. The longer the better really. Here
is a good guide for applying Klasse SG.