Depending on the state or country, infidelity has no bases in what happens in court. Judges don't care about the inner workings of the M. They will only care about the assets and kids. With that being said, states like TX divides all assets 50/50 mostly. No hassle for the judges. So don't let continue trying to collect evidence about her infidelity to use against her in legal battles.
If you don't have definite proof then fall back on confronting her. But if the proof you have is clad tight, then you don't need anymore proof. The only thing you need to know, was that she had no doubt cheated. The amount of times and with who don't matter at this point. She is cheating and that's all you need to know to move forward. So when you confront her about what she has done, you are doing so not in an attempt to beg her to stop, but to explain, that you won't tolerate the disrespect.
In the book, "love must be tough", and the doctor speakers on confronting your Spouse about cheating. If you can, read that book, before you confront her on her infidelity. It can help give you a road map to tackling that situation.
IMO, you have enough evidence, you don't need to know who the guy is, even thou you have a strong suspicion, the problem is not the OM, it's your WW. All your focus needs to be on yourself, telling her what you will not live with and tolerate. There will be a strong urge for revenge, but remember this is about your WW disrespect and not trying to get back at the OM. Forget about him.
You will have to establish boundaries, no matter if she's decides to stop or continue in the direction she's going. Your boundaries will need consequences. Most LBS struggle with implementing boundaries and holding their spouses accountable, if they cross those boundaries.
Lastly, if she denies, then you look her in her eyes and say, "you are a liar, and what you are doing is not right". Don't say anything else, don't stand around to give her a chance to manipulate you.
Take your time, and think of boundaries you can tolerate being cross, and figure out those consequences, Once a person cross your boundaries, you can't go back on the consequences, after you inform them, of what your consequences are. I use them, because your boundaries shouldn't be cross by anyone
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Onward and upward
M:37 W:37 T:11 M:10 S17, S13, S10, S4 BD:06/28/17 OM confirmed 07/20/17 Recon the M 10/29/17 Working hard:2gether
Onward and forward
This process is not a sprint it's a marathon! Patience, Patience, Patience.