Okay. Well, I think once you disclose the DUI (and you pretty much have to) as Alurra71 said, your spouse will be criminally inadmissible to Canada, and that will be fatal to your application. It looks like you won't be eligible to apply for criminal rehabilitation until January 2017 at the earliest. Unfortunately, that's just the way it is under Canadian immigration law. It sucks, I know, I am going through the same thing right now with my wife who also had an old DUI.
I think you have 2 options at this point;
(i) Wait until January 2017 to apply, or;
(ii) Apply now, get rejected and appeal on humanitarian and compassion grounds. You'll certainly need a lawyer for the appeal. You're probably looking at about a year to get rejected and then a year or so for the appeal to get dealt with. Your appeal may or may not succeed.
Choosing option (ii) will probably take you into 2016 anyway. Maybe option (i) is your better choice.
Although I agree with the other posters who say you don't need a lawyer to do a typical PR application, your case involves an question of criminal inadmissibility. That's a serious issue under Canadian immigration law. You might want to consider a consultation with an experienced immigration lawyer at this point to see if you have any other options.
