Best baseball bat for 6, 7 and 8 year olds

My boys have been playing tee ball and coach pitch for the past three years, and I recently decided to take the plunge, sacrifice a few hundred dollars and buy a good bat. 

I have spent a lot of time researching bats over the past few months, and while there are some good sites out there, I did not see a lot of help.  In fact, several of the comments I read suggested that the kind of bat did not matter, and teaching fundamentals...swing speeds, etc... For the novice or child just starting out, this is not bad advice at all.  However, I disagree on that point for several reasons for the more advanced player.

The best comments I saw through my research were that each child is different, and it is important for someone to test bat sizes and lengths with their own kid.  Through my experience in coaching, I could not agree more with that comment.  I have for kids that as of January, 2011 are 7, 6, 4, and 2.  My 7 year old used a 27" bat as a 5 year old, moved up to a 28" when he turned 6, and has moved back to a 27" in his first two seasons in coach pitch.  My second boy is using a 26" bat as a six year old in tee ball.

However, there are all kinds of things that will guide you in the right direction if you are simply an online shopper, or don't know where to start.  Should you get composite?  How about barrel size?  Drop weight? Is bat speed more important or sacrifice it a little for a larger barrel?

When it comes to composite choices, if you are in a league that is designed for Little League play, composite bats are outlawed, so you will be sticking with the aluminum bat.  It is my recommendation that you go with a 'drop 12' (-12) bat to maximize bat speed for anyone from the ages of 5-8.  If you are playing solely on a tee, you can afford to go with a little larger bat size to make the ball go further.

The league we play in is designed for Pony league play, so for the time being, composites are not officially out of the question.  There are some pony leagues in areas around the country that have formally announced that composite bats are not allowed, and some that say they are welcome.  By tournament time, I would expect that there will be a formal announcement by heads of all Pony leagues.  For now, they have protected themselves by being vague, saying they allow metal, aluminum, and graphite bats with no mention of what might qualify as composite.  They have, however, issued a statement lowering barrel diameter to 2 5/8" vs 2 3/4.

Basically what all this means is that if you have an advanced player from the ages of 5-8 and want to take that plunge to spend $200 on a bat, I recommend Mikken or ComBat for Pony league play (senior league bat, 2 5/8" barrel size, drop 10) 1 piece composite bat.

I welcome all comments and am looking for feedback.