[DonutDeflector]

Hello, I'm looking for headphones and an Amp/DAC for my brother who is 10 years old. He loves audio as much as I do. I may have taught him the ways of the Audiophile. I'm looking for a headphone that's a jack-of-all-trades. Good for gaming and every kind of music (mostly EDM), and is very comfortable to wear for long periods of time. All the rest can be anything you want.

I also need an Amp/DAC for these headphones. He will use these at home most of the time. Mostly on his MP3 player and sometimes on his PC.

I need the headphones and Amp/DAC to fit in a $200 budget.

(I'm getting this for him because he's giving me a Schiit stack.)

 

[399942]

This one is a bit tricky because finding a pair of headphones in that description in that price range is easy, but once you want an amp/dac (usually not so cheap to find a good one), things get harder. Since he listens to mostly EDM, games, needs them to be somewhat portable (assuming this because he's going to be using an mp3 player with them), and comfortability is important, I'd recommend either DJ/Studio Monitor Headphones, or just something more bass heavy. As for an amp, You'd definitely want to go with a Fiio Amp/DAC. they make very good low cost stuff. Personally, I'd get the Fiio E10K, I own one and I'm very happy with it. It's low cost will allot you worth more money for headphones. 
As for headphones, there are lots of them in this price range with these requirements. I'll throw a few out there, then have you decide which one you think will suit his needs best. Sennheiser HD448, Sony MDR XB700 (these are alright, but the bass almost drowns out the mids and highs), Audio Technica M50's, Audio Technica Pro 500MK2 (Comfort might be an issue with these, you may want to consider replacing the ear pads on these, or break them in really good), to name a few. For me that's all I can come up with without more extensive research.
 
Also, I like how you're starting them young, so you can get them sucked into our money draining world even earlier

 

[DonutDeflector]

This one is a bit tricky because finding a pair of headphones in that description in that price range is easy, but once you want an amp/dac (usually not so cheap to find a good one), things get harder. Since he listens to mostly EDM, games, needs them to be somewhat portable (assuming this because he's going to be using an mp3 player with them), and comfortability is important, I'd recommend either DJ/Studio Monitor Headphones, or just something more bass heavy. As for an amp, You'd definitely want to go with a Fiio Amp/DAC. they make very good low cost stuff. Personally, I'd get the Fiio E10K, I own one and I'm very happy with it. It's low cost will allot you worth more money for headphones. 
As for headphones, there are lots of them in this price range with these requirements. I'll throw a few out there, then have you decide which one you think will suit his needs best. Sennheiser HD448, Sony MDR XB700 (these are alright, but the bass almost drowns out the mids and highs), Audio Technica M50's, Audio Technica Pro 500MK2 (Comfort might be an issue with these, you may want to consider replacing the ear pads on these, or break them in really good), to name a few. For me that's all I can come up with without more extensive research.

Also, I like how you're starting them young, so you can get them sucked into our money draining world even earlier

Thanks! Making him buy me a Schiit stack for this though! I'm guessing his first paycheck with go to some headphone gear right away. Hehehe.

Yes he will be using this with his MP3 player through an Amp/DAC but he will stay home most of the time with it as well as go outside a little. For on-the-go stuff I'm letting him borrow my FiiO e6 Amp.

I'm shooting for those m50s though!