Recommendation on a modding service?

I wanted to ask the community to recommend or note a modding service. I am going to upgrade an anthem 225 int. The amp at $1600 is unbelievable, but the substitution of higher grade parts would make it a giant killer. And as we all know products are designed to a certain price point. I love the sound and power of the unit and want to squeeze all I can out of it. Thanks!