That's a pretty vague request, that it isn't specifically broken, just needs "gone over and tweaked". It seems like an invitation for someone to just take it, sit on it, and hand it back and charge $$$.
If it had specific problems those should be handled on a case by case basis. If he is instead hoping someone can turn an off the shelf product into an audiophile's dream, that seems outside of realistic. It also seems like the cost to do it would exceed the value of the amp by not just 1:1 but instead be enough that there is no reason to start with the amp instead of getting a different amp. I am not knocking the Pioneer SX1280, just saying that a mass produced product, if you can't tweak it yourself, then you're probably better off starting over with something else.