The best way to do this is to contact, directly, lawyers in the area who handle this type of case and who work in the court you are going to be in.
Since you have already found AVVO, I suggest you type in DUI in the search area of the county in which you were charged. Call lawyers from that area directly, and let them know a little bit about you case.
Generally lawyers charge by what needs to be done and it is hard to say from your question - they will examine your case for possible trials or pleas, etc, and that is very detail oriented.
You should definitely interview some attorneys - 2 to 5. Many attorneys will sit down with you at no charge and generally discuss what to expect on your DUI case. You should know your exact court and prepare a short summary of the event and have a list of specific questions that you want answered. I expect to spend between 15-30 minutes with a potential client and generally do not charge for an initial conversation.
When interviewing the attorney, you should see whether you are comfortable with the attorney, his/her office, his/her staff, and have an idea whether that attorney will be the one handling your case. You also need to determine whether this attorney has the time to devote to your case.
No one likes paying fees. But, remember if your attorney charges lower than average is the attorney staying in business by having a large volume of cases? If the attorney spends alot on advertising and charges very little - how is he/she paying for this. You need to understand the economics of the practice. If you charge discount prices, you have to make up for it with a HIGH volume of clients. So, paying a small fee may mean getting a small amount of attention.
Finally, you should always get an attorney. The prosecutor and Judge are not there to assist you, they are there to convict you and end your case as soon as possible. It is up to your attorney to advocate on your behalf.