Personally I would cut back on the caramel malt, just leaving the Special B. Since you're doing extract, you could replace it with some Munich LME. Are steeping or mashing? If you're mashing you could just do a PM with Special B, Munich, and some Aromatic. The problem with that much caramel malt is that it will leave too much sweetness, and a good Belgian ale is going to be on the drier side.