Help with Game Grrl mods

[guitarbuilder]

Hi
I am a new user. This is my first post. I want to get this idea I had to work, but I can't seem to figure out how. What I want to do is have a gameboy-style handheld console, but instead of playing cartridges like a normal gameboy, it plays gameboy, gameboy color and gameboy advance ROM files. What I want to do is build one of those Game Grrl consoles where you reverse engineer a few components and put them together to create the console. But the problem is, that only plays NES games. I want to be able to play gameboy games. Specifically the pokemon games and super mario bros deluxe (the gameboy color version not the gameboy advance version). So what I have to do is modify the Game Grrl so that it will play the Gameboy ROMs. I know that there's the Dingoo a320 out there, but I want to challenge myself to do this. I'm determined to succeed.
My question is how do I do this? I have a few options that I came up with in my head or found by doing some research:
I can somehow modify the NOAC so that it has the gameboy files instead. This could probably be done using a computer. But I don't know exactly how
Using the NOAC as a basis, I could put the ROMs on an internal memory and work that somehow. I'll need an internal memory of some sort to store the Save files
This one is more complicated. Using the Game Grrl's enclosure, LCD and NES controller buttons as a basis, I could install a processor and other components like in this diagram to run a gameboy emulator. But, unless I'm wrong, I have to create a circuit board to do, which I am nowhere near doing. The nice thing about the Game Grrl is that you just reuse old components and solder them etc. There's no creation of circuit boards or anything.
http://focus.ti.com/docs/solution/folde ... t/473.html
Or could I also use this diagram to do it?
http://www.fairchildsemi.com/markets/ul ... aming.html
Other mods I want to make are an on/off switch and a headphone jack with a wheel potentiometer, which I know are possible. But some other possible mods I want to make are a USB connection to add/remove ROMs and back up the save files, white LEDs as a backlight because they are more energy efficient and some sort of a video out connection to connect it to a TV. These may be impossible, but they'd be really cool
Please help me out with any answers you have.
thanks
guitarbuilder
P.S. If you know a way to make a gameboy-style device that plays and saves ROM files other than how it's done here, please let me know

[J.D]

You can easily do this with a flashcard and a Nintendo DS. Just buy the flashcart, get an SD cart, put the firmware on the cart, put the emulator "Lameboy" on it, and put the ROM files (and Lameboy) in a folder. Run Lameboy, and you can play GB/GBC ROM files.

There are also GBA flashcarts you can buy, and you can run GBA ROMs on them.

[guitarbuilder]

I've heard of lameboy. But I want a real challenge. So either I'm going to mod a Game Grrl to do this or build a portable media player or portable gaming device from scratch.