I have used silver SoLite as well as other SoLite colors, plus many other brands. The silver SoLite isn't as transparent as the lighter SoLite colors (yellow & white, which I've used), but you'll still see a little bit of structure through it. I've got one glider that uses silver SoLite for the fuselage, so I'll try and take a picture that shows what it would look like.
From memory, I think it would work pretty well for what you want and would certainly be light enough to not crush any structure. I guess the bottom line for me is if MM recommends the lighter covering I'd go that route with SoLite or a similar covering.