STYLETHREAD -- LET'S TALK SHOP!

Hi all, hoping you can help.  My  13 year od son is having his 8th grade promotion ceremony and dance in a few weeks.  There is a dress code for both of these events.  Basically the boys are expected to dress up in slacks (no jeans) and dress shirts.  We live in a fairly nice area in Garden Grove (Orange County, CA) so no one really thinks it's a big deal to make a big event out of the kids accomplishments and milestones.  Sooooo...I need to go shopping with him. I was thinking a pair of slacks and two different tops, figuring he could wear the pants for both events and just wear different tops. 

Here's my first issue:  I naturally want him to  look stylish and not cookie cutter or boring.  Well, I don't really know where to shop for him.  I'm thinking I will start with places like Khol's, Forever21, H&M, and Macy's. But honestly I don't know if I will find something that is young, fresh, stylish, and dress code appropriate at these places.  So if any of you have any idea of where I can go, I would really appreciate the info.

Next dilemna:  The weather. Living in sunny California he can't wear a suit like he originally wanted to.  He would totally fry considering that the ceremony is outside. I would absolutely love for him to wear suspenders and a bow tie with a nice shirt, slacks and maybe converse.  Another option I thought about was a vest.  Not sure if he will go for these ideas so I want to make sure I have a good vision that can be relayed in a manner that he will be excited about it and not just shoot it down because it was "Mom's" idea.  I have been putting together a file of pictures/looks that I think are age appropriate, stylish, not stuffy, dress code approriate, and hopefully interesting to him.  I am looking for ideas from you girls,especially you younger ones, that might interest him.  If my ideas are lame please tell me! I don't want my kid looking like a dork. 

Here the pics/looks I have found so far:

Oh yeah...if it makes a difference, he is very lean and tall for his age.  More like a solid thin not a lanky thin.  He wears clothes well and has a good body shape that pretty much allows him to look good in just about anything.  He is very athletic (football, baseball, basketball, skateboarding, etc).  He normally dresses very casually in a skater style. Loves baseball hats. Likes to coordinate. His skin coloring is very siimiliar to the first picture I posted (he is half black/half Mexican) so if you have color ideas that would compliment him please let me know. 

Wow! Long post...sorry   I just really wanted to give you all the info in hopes that you could help me.   Thanks so much for any ideas, suggestion, and opinions you share with me <3