I will be offering to sell case halves when project done, will be making a single video showing the whole build process including making the portable, and yes, will be offering to sell a small number of completed systems over the months coming for a very fair price. As this system will be far faster to assemble, the cost will be very reasonable - will price it up when made the first system.
The goals of this project are:
* Make a vacuum forming case that's easy to hold and looks pretty
The case i'm making is a large format style GBA original as that looks nice and is ideal for this project. The front is flat for buttons and screen to lay properly, the back will be shaped so the sides are 35mm thick and the middle around 55mm thick. Easy to hold.
* Easy to mod for anyone who can do basic modding and basic soldering
This project will not require board trimming or cutting so therefore easy to assemble, no complex wiring (although the controller will need some wiring if using a memory or rumble pack).
* A case for N64 and SNES
It'll need two case moulds made for the backing probably, unless can make just one, but this will be done.
* Good specifications
System will be fine for using 3 sets of the cheap Canon BP-911 Li-ion cells, giving 6 amps which should power the portable for around 4.5 to 5 hours. An expansion pack or jumper pack can be used, and for the controller a rumble and/or memory pack (both if a dual card).
I rather like this look, so using it, and will be incorporating scaled up shoulder buttons, etc.
A PSone screen looks fine in this too, proportionate to the scaled up GBA screen:

Made the case front out of MDF (wasn't easy), the backs will be made from clay:

Holding (not easy to take a pic at an awkward angle), lol:

All will fit nicely, good joystick from a MakoPad / SuperPad 64; you can use smaller ones of course; space for fan, all fits nicely; so without board trimming, about as good a size as it gets:

