We have teams here loaded with tall and strong boys, but a couple of the boys are not so tall. Those boys are some of the STRONGEST boys on the teams, though. What they lack in height, they more than make up for in strength and/or energy level. Also, I believe that every single player that made our varsity team has been also playing travel. I do not know that it is so much that they are "on a travel team," that is key, but they TRAIN and PRACTICE when it is not in-season for school. So if you do not play travel, find a way or a place to train. If you REALLY want to play, do not be deterred - control what you can, which is actually quite a bit.
Showcases are really only valuable if you have skills to showcase. If you are hitting top numbers at something or you have a skill that would be notable, then it might be worthwhile.
Best of luck!