The problem you'll have at 6u is there won't be hardly any 6u teams so you'll have to move up and play 7u squads and unless you just have some insanely talented 6u kids you won't be able to compete with even the lower level 7u teams. Most all star teams I've seen that try travel ball end up getting hammered every game.
Travel ball is what you make it, you can do it on the cheap and play 5 or so local tourneys that are typically Saturday only and it'll cost you about $25 per kid per tourney. Or you can go to Cooperstown and drop 5k, if that's your thing go do it and enjoy a family vacation at the park, people spend money on stupid crap everyday it's all in what you make of it. My kid plays travel ball, we love being at the ball fields, my kid loves it and it's time well spent together. It ain't cheap, especially as they get older. There are a lot of myths out there to travel ball and unless you're under some big organization you can probably stay within an hour of your house and play as many travel ball tourneys as you want and most of the time probably won't play more than 4 games, travel ball has gotten really watered down compared to what it use to be.

All that said, I'd recommend you move your kid up an age division and let him compete at the rec level for at least another year. Travel ball isn't a cure for bad fundamentals nor solution to playing better competition especially at a young age.