You want to find a professional company design at least 600 / square. The kind of 100 up and down my advice do not find, do their own design and professional company design is not the same. But there are higher, the design company ability is not the same, save time and final results are not the same.
Professional design basically to include renderings, construction drawings, as-built drawings.
Some things are not there on the line, do to do a good job is very important ah!