Really cool design and idea, I'm currently in school taking intro to both AutoCAD and Solidworks.

Excellent! 

Not many developments since the last post, tweaked the design slightly but not enough to warrant a new render yet. I'm in the middle of moving at the moment but hopefully jack sockets, batteries etc will arrive within the next month and I'll be able to print the first prototype case in the next 8 weeks!

Very excited about these!  Any news?

I'd really like one of the clear ones

Detail hasn't been removed, just can't be bothered to convert the whole wireframe to a solid right now. But yeah, cut quite a bit off the top and bottom so the shape has changed slightly! Just realised I forgot to do the speaker holes. They still exist, just not rendered, this is just to show the change in outline:

Think I'm just gonna go for full USB port, there's space on the case and I don't think it'll compromise anything else. If I can find suitable panel mount mini/micro USB connectors at a reasonable price I'll definitely opt for them instead. Really don't want to jury rig it/be using glue!
There's a panel mount connector on the charging board I'm using but I'm not sure of a way to use it easily without extending it.

Speaking of, did you have anything in mind for that already?

Micro USB seems like the go-to charging connector for this type of thing. However, my searches for panel mount Micro USB connectors in the past have shown they're always expensive (~$10 a piece) and physically bulky. It might be simpler to use a PCB mount connector (either on a breakout or built into the LiPo charging board).

Or you could use a different type of connector entirely. That's an option.

That's great, I hopefully will in September as well! Will have to see if I need to make friends with an engineering student first though.
It's probably gonna be longer than I thought before I can make the first prototype unfortunately. Need to wait for panel mount ports for charging, batteries, jack sockets, frontlight kits and screws to arrive first!

I have access to free 3D printers at my Uni, so I can do some proto prints. FOR FREE.

The Start/Select holes are probably designed to re-use the existing buttons from the GBC. Changing them would require designing and manufacturing new silicone pads/buttons (which is possible, but probably too much effort).

Looks good, I think the start/select buttons look a little out of place though. Maybe they should be bigger?

Currently no, just started this project with GBA in mind. Any progress and 3d designs I make will be uploaded on Thingiverse and here. As far as the front light kits go, they fit well in the original GBC case, with two small(28 awg?) leads coming from the left and right sides. Should be easy to work in, especially if you're bonding the frontlight to the LCD via LOCA.

Agreed. I've never fitted a frontlight kit from kitsch bent, what would need changing in the design? Will be ordering one in a couple of weeks.

Are you posting progress online anywhere? Would love to see!

Cool, thought I'd chuck some thoughts out there anyway. Either way I'm definitely interested in this project, and I'm also currently working on resin casting cases. I'd love to see this come to life.