Your B&W are a perfect match for the McIntosh amplification. However they can be a little stogy in the midrange.
Another excellent match with Mac amplifiers are the Klipsch Heritage.
The Forte IV sound excellent paired with your amplifier. The Forte IV has a lively deep and rich sound and is the more refined than the Heresy.
Be prepared for a more exciting sound and much more life like midrange,
Should be able to find new under your budget.