ribbon speaker for HT - beginner

[big doggy]

Hi all. I am wanting to upgrade my home theater speakers. I am a beginner so please bare with me. I currently have North Creek Audio CM7's which is a MT with the MtM as the centre. I also use 2 TC sound 15" subs stereo with SMS-1 for equalization. For power i am just finishing my UCD400 multi channel amp. Ok, i am hoping to find a system that will incorporate a ribbon tweeter.... i liked the Raven but see it is not shielded and although i use my drop screen for movies, my plasma sits behind and is not more than 1.5ft away. I dont mind building the boxes, i can work at a cross over, thinking of a sealed design, space not really a concern but would prefer them not being a floor standing model. So would i be better off runing a MT for all but a MtM for center? or three MtM's upfront, and 4 mt's for surrounds? also, want to consider better mids like Focal, ofcourse shielded as would be the ribbon. any suggestions would be appreciated. Thank you.