Instead of a triangle set up I would try (if possible) either move the speakers closer together (6ft apart) or move the sofa back another 5ft. I would play with the toeing too if you can try either of these suggestions. You should gain depth by moving them farther from the back wall. Can't argue with the cost.
At 85db they are not too efficient (love current). But the imaging will be better. I have the C1's and the B&w 802d and 803d were on my list for for 'full range' speakers but full range and my room don't get along too well. Should be great for your room in my opinion.
Last you may be surprised how a more power amp may sound.
Just my opinion
Thinking of a great smaller speaker that may be more efficient with better imaging (Dynaudio C1 is being considered).
At 85db they are not too efficient (love current). But the imaging will be better. I have the C1's and the B&w 802d and 803d were on my list for for 'full range' speakers but full range and my room don't get along too well. Should be great for your room in my opinion.
Last you may be surprised how a more power amp may sound.
Just my opinion