Get them heat molded, it will help a lot.
I didn't find breaking my Elite Plus to be that bad, minus the reaction I had to the rubber on the tongues (which I am assuming won't be a problem for you, since you're wearing the same boots now). I was just getting back on the ice too, so I was not only breaking in new boots but getting my feet back under me, and it was really not that bad.. I did leave the top hooks undone for a very long time but I wasn't really jumping much during that time, so it wasn't a problem.
My Elite Supremes (90 stiffness) felt absolutely fine from day 1 - a little "different" being new boots, but I was jumping and spinning in them right away, and it only took me a session or two to feel completely comfortable in them. I only left the top hooks undone for a couple of weeks. I think you will do just fine with your new boots - you may or may not notice much difference with the blades. I think the stainless steel runners feel a little faster/smoother on the ice, but as far as the weight difference, I really didn't notice anything when I switched to my paramounts.