Carb Rebuild -- Suggestions for where to go

I need to get my carb rebuilt. It's a Marvel MA4-5 off an O-540.
Somehow it floods to the point of not running (longer story possibly
in another post). I'd like to find out why this is happening so that
besides just getting an overhaul I actually know it won't flood again.
I don't care if it costs extra for the diagnostic as long as I know
who I'm dealing with will find the problem to whatever extent this is
possible.

Any suggestions on reputable shops and previous experiences would be
greatly appreciated.

Thanks in Advance for any replies.
z