Quick solution for single sub in a box with an amp.

[SFBay69]

In a quick and dirty fashion:

I'm very tall and the seat will be all the way back. I moved the tank to under the bed. I don't need to upset neighbors or make dogs' ears bleed. I have an updated AM/FM original radio with 180W to power 2 3" dash speakers and 2 5" kick panel speakers. Is there a single sub (sealed), in a box, with an attached amp out there for a little low end upgrade? It's a 69 C/10 shortbed. Again nothing crazy on pounding bass, just a fuller sound. Price isn't a huge concern but the truck is mild and clean. I don't need the stereo to be the biggest feature. Thank you all in advance.