CanI find a speciality lawyer who only deals with replying to NOID's?

Closely reviewing the content of the Notice of Intent to Deny (NOID) will be critical to determine the basis on which the USCIS does not think the evidence is sufficient. The response to the NOID is governed by the points raised in the NOID. You may refer to the AVVO practice guide I wrote titled "Best Practices in Responding to a USCIS Request for Evidence." Much of the information also applies to NOIDs (the section of the regulations providing for RFEs and NOIDs is the same). If you do not submit a timely reply, your wife's petition will be denied. If the NOID suggests that USCIS thinks your marriage may be fraudulent, not responding is almost a concession, and could come back to haunt you in the future. You are correct that you have to prove that the intent of the marriage was right. How to best do that, again, depends on the contents of the NOID. You should definitely not hide the fact of your separation. Being "diplomatic" can unintentionally result in a charge of misrepresentation or fraud. See my other practice guide on "Immigration MythBuster" regarding pursuing a green card by a separated couple. Candid disclosure by you and your wife is often the most successful strategy for this type of case. Since your wife was kind enough to let you know about the NOID, perhaps she could still be persuaded to assist if an attorney assured her that it would not be too much of an imposition to help, that failing to adequately respond might reflect badly on her, and also leave you vulnerable to deportation from the U.S. Certainly you have the option to not reply at all and move on. But you should be aware of the legal consequences of doing so, since sometimes "moving on" means "moving out". Good luck.