If you are following neal's advice and are nailing beams together I would go with this approach. You will have to remove some drywall to do this.
If you are getting this inspected an inspector would like this alot better. They love brackets. I think they all get a monthly check from Simpson Strong Ties.
If going the other way I would stick with the seperate beams and also go crazy with nails and structural screws. Attaching a 2x4 length wise to a 3" wide beam will not work unless you go crazy with L brackets.