Hi Pundamilia,
I have had the Sopra 2's for almost 2 years now paired with BP26/7BSST2's. Its a wonderful combo. I sometimes think the soundstage this combo produces is almost to big for the 8' x 14' back wall. The stage also goes about 6' deep from slightly in front of the tweeter plane to the rear wall. I bought the 7Bs 8 years ago when I had a pair of Infinity 9 Kappas which are notorious amp killers. The Sopra's are a walk in the park compared to the 9 Kappas so if you want to spare some budget you may want to consider the 4B3 with the new BP17 cubed preamp. In fact I have that move under consideration. With way lower power requirements and a tad smaller listening room (14' x 25') the Sopras would be easily driven by the 4B3. I talked it over with Gary Dayton at Bryston who agrees. Hope this helps.
Bill