I don't claim to be an expert on in wall speakers but since you don't have any luck getting responses, this is how I would do it. Plenty of well respected speaker manufacturers offer in wall speakers. If you are a fan of B&w, for example, why not look at what they have to offer. At least its a starting point.
I know you don't want on wall speakers, but have you considered the cost of installation? Unless you cut into the walls and run the cables yourself, that could be a very big portion of your budget. Possibly a compromise? Maybe just a small pair of speakers for your main L & R channels and do the centre and surrounds in wall. Its just an idea. You would save money and get better sound where its most important.
I know you don't want on wall speakers, but have you considered the cost of installation? Unless you cut into the walls and run the cables yourself, that could be a very big portion of your budget. Possibly a compromise? Maybe just a small pair of speakers for your main L & R channels and do the centre and surrounds in wall. Its just an idea. You would save money and get better sound where its most important.