please look here:
I’ve got a great uke track that has just what you’re looking for—a nice intro that bursts into full swing. Includes seamlessly loopable variations as well.http://audiojungle.net/item/a-bright-idea/3455865
Here’s another upbeat/energetic option with similar start:http://audiojungle.net/item/a-whirl-of-activity/2906445
Thanks for listening!