The center is discontinued, it is a Kef iQ60C. I found a retailer in the UK that has it. Leaning more towards a iQ30 bookshelf as a center, I have always heard about matching the front 3, but I am not expert. I definitely can not use the iQ90 as a center.
Would a Kef Q200c work? Same tweater, although woofers are different sizes and different types.
Still on the fence. Good conversation keep it coming.