Avoid use of the word "guarantee" - too many legal implications. Pick something that is less laudatory so that it can be registered as a federal trademark. Phrases like, “Hey, we are great” or “Our service is terrific” have a hard time getting past the United States Patent and Trademark Office, which means you stand a harder time if you ever want to exclude your competition from using your slogan. In other words, use something more original and distinctive so it can be yours exclusively.
I hope you have liked the various slogans here.
This is what I can think of:
Outdoor sports gear you'll love. Satisfaction Guaranteed!
Being an outdoor sports fan I always look for high quality sports gear. I live in Melbourne, Australia where we have this outdoor sports club and our climbing wall is famous for best the best in the area. We would love to promote your sports gear if you'd like us to.
Johan