Business Valuation buy-in help?

In NC and looking at possibly buying into the firm I currently work for, but want to make sure I'm looking at all the financials correctly and evaluate what they have presented to buy-in. It seems high (which I get, they want as much money as possible), but things are a little slower lately and a key person would be leaving the firm at the same time so I'm concerned about how that affects future numbers. I've spoken to a lawyer already, but from that, think I need a cpa or financial person. I've tried to google and ask folks I know around here, but having trouble finding someone that seems qualified to use for this because I feel like there is nuance to the evaluation and not just looking at EBITDA,w etc. Anyone have any recommendations? Thinking they don't have to be local if they have experience with similar tasks.