Since you have an adjudication on your record (trespassing), you do not qualify for sealing or expungement for that conviction or for the newer case. There is a two year time limit on motions for post conviction relief, so you are 8 years too late. Unfortunately, it appears you don't have any relief available to you.
Assuming this is the only criminal case you have ever had, and that you are not currently on probation for the offense, the case would not bar you from possessing a firearm or constitute grounds to deny your concealed weapons permit.
Although I don't know Joel personally, he is by reputation an excellent attorney.
"Pro bono" and "reduced rate" are mutually exclusive. Either an attorney represents the client (pro bono) or he/she is willing to provide representation at a reduced rate. If someone is indigent and can't afford an attorney, then the court will either the appoint the federal public defender to represent your husband, or, in the alternative, appoint a qualified private attorney from what is called a CJA Panel. If you can find someone to represent your husband pro bono, then that may be fine....