if you want texture, and your dash is black, first try truck bed liner. It's cheap (like 5 bucks a can at walmart), super durable, and it has a nice texture that you can kind of control by holding the can further back or closer to whatever you're painting. I used it on my door panels and on my sub box and they turned out really nice looking. If you have any imperfections in your box or fiberglass work, this will fill them in great.
That said, if you're worried aobut matching colors or about the texture, do a goodle search for SEM texture spray. You just spray this stuff on until you get the texture you want, and then you spray on a vinyl-dye that SEM also makes to color it. SEM has a ton of colors that match up to pretty much any interior piece.
heres some pics of the spray i used
texture before:

texture after: