My idea was the make the cp box, and cut notches to fit over the sides of the cp area in the cab frame and hiding them. I was going to get metal brackets to screw into the box and the cab frame on both sides for stability.
Panel clamps and brackets are pretty standard, combined with resting the weight of the panel on the existing cab frame so that not all of the weight and abuse is going straight into the brackets alone.
Whatever you do, you will want to make the panel easily removable. Screwing it into brackets rather than securing it with panel clamps will make it difficult WHEN you need to do work on the control panel. usually a combo of panel brackets and some butterfly bolts will do the job of securing it to the brackets.
One concern is how strong would that be if I'm using mdf wood, my concern is the weight.
I wouldn't worry about the weight, as long as most of the weight is taken by the cab.
I also measured and the cp box would be about 6-7 inches in height, is that normally enough room?[
That's more than enough, unless you're using deep controls like an up-down spinner, or some other exotic control. Joysticks and buttons don't need much depth. Even with a big spinner/trackball, you shouldn't need that much depth.
That said, if it were me, I'd try to follow the contours of the cab shape, rather than flattening it out. Most cabs in the wild have somewhat of an angled control panel.
I'd be looking for an authentic control panel for that thing. Anything else is just going to feel weird to you.
Personally, I'm not much of a purist, but I do like decent aesthetics. Not much of a fan in general of CPOs that don't look like they belong. But... it's a generic box cab so

My typical approach is to try to do no harm, but otherwise do what makes most sense to me.