The strategy and what evidence will help your husband are best discussed with an experienced criminal law attorney. You are not going to receive a decent answer to your question through this medium. I am sure that any decent attorney will bring all those facts to light when and if it ever gets to trial. You should not wait until he is convicted to try to then win the case. As is, it is an uphill battle. Find and hire the best attorney you can afford. Go and meet with them before you hire them. You will get a better sense of whether you like them and they are a good fit for your husband. Most offer a free consultation, so use it to your advantage and tell them your story.
Legal disclaimer: My answers are only intended as general legal advice based on my experience. They are not intended to be a binding legal opinion nor to create an attorney-client relationship.
If he has a new charge, he needs a defense attorney to handle this for him. As for the case he already pled to, you need to consult an appellate attorney. Buyer's remorse is tough to deal with when the defendant entered a voluntary plea. The legal arguments to undo this are few and far between.
Macy Jaggers's answer to a legal question on Avvo does not establish an attorney-client relationship. Ms. Jaggers offers everyone a free consultation to discuss their case. Feel free to call her office at 214-365-9800 to make an appointment (phones are answered 24 hours) or visit her website at www.macyjaggers.com for more information about her services and recent victories.
You need an experienced criminal defense lawyer to fight the new case. From what you've posted, there will be a LOT of work and time involved investigating this case. Regarding the old case, there is little you can do if you were caught up in a sting and the government's conduct did not rise to the level of entrapment. The exception to this might be if your lawyer was so terrible that he/she didn't even provide the minimum required representation. Such a claim must be raised in a habeas proceeding.
*** The fact that you solicited advice over a public forum waives any attorney-client privilege thus far. In addition, communications over this forum do not create any attorney-client relationship. To have a privileged conversation and/or establish an attorney-client relationship, contact me using the following information: Peyton Z. Peebles III Capitaine, Shellist, Peebles & McAlister, LLP, 713-715-4500 (office) 713-715-4500 (cell) Peebles@TexasLegalTeam.net www.TexasLegalTeam.net