Thanks for the feedback fender3x! It should be a lot of fun (and my biggest challenge yet!). The pre-amp I've been looking at is the Fishman Powerchip. Luckily with this being directly attached to a pot I think I could make it my front volume control knob and use some of the extra routing in that area for more room. From the research I've been doing it should have the setup I need for the purpose of this build:

https://www.amazon.com/Fishman-Power...4014812&sr=8-1

The speaker is the part I'm willing to accept leaving on the drawing board. I'm waiting for it to arrive to do some testing and fitting first. According to their website it works as well for bass as for guitar, but if not, I've got a defunct NES classic that I can gut and turn the housing into a speaker instead.

Either way though, if both can fit it will require a lot of routing being added to the back of the body, so it's all going to take a lot of planning. Should be a little easier once it comes in and I can plan, but we'll see how it all goes!