Both of these tag lines are by far the most commonly used tags in the industry. "A Full Service Sign Company" is the most used of all. Also, unless you do every aspect of the sign industry (electrical, fabrication, wide format printing, signs, etc.) then I wouldn't call myself that. Come up with something unique, set yourself apart.
Another very commonly used quote: "a business without a sign is a sign of no business"
Stay away from that one too!!