You CAN stain after the glue up.
you CAN follow a nice sharp glue line with the stain.
It just takes time, a small brush ( bout the smallest artist brush you can find), and lots of patience.
I've done it.
The problem you might run into is if some of the glue has penetrated into the wood you want to stain.
The stain doesn't like to stain the glue.
You just let the stain bleed to the line.
Started like this...
turned out like this...
With all that said, I think it would be WAAAYY easier, and most likely look better to use blue spectraply..or whatever "ply" wood.