From the specs of your first camera to the newest technology photographers can become gear obsessed. While gear is important it's not the most important tool at a photographer's disposal. Many times when I pull out my equipment the response "wow, nice camera, it must take great pictures!" Sure my camera processes a nice image but making a photograph happens mostly between the photographer's ears.
The photographer's experience and personality will have a bigger impact on the quality of your portrait then their equipment alone. One night I was out taking some personal pictures when I saw someone that I thought would make a great subject for a photograph. I approached the group that were nearby and asked if one of them would pose for me. She agreed and we went on to make an interesting picture together. I couldn't have made that picture without a special piece of equipment that I had with me called a PixelStick but the gear wouldn't help if I didn't have the conviction to ask a complete stranger to pose for me.
When hiring a photographer you want one that uses the best equipment they can afford. More important than their equipment you want a photographer that has the experience you need to get the picture you desire.