What about Yamaha DXS18
I'll echo the suggestion to look at the Yamaha DXS18. We got one for our portable church a few months back and it is very, very impressive. I've used JBL PRX and QSC KW subs (to compare a couple others in that market segment) and I like the Yamaha sub better than either of those other options. We use just one in a 600+ seat school auditorium each week and it easily fills the room. If we didn't have to set up and tear down each week, I'd love to add a second one just for the added displacement.
We also went with the Yamaha DSR112's for tops, partly based on multiple posts here discussing how good they are. They are arguably the best powered speakers in the segment, and the size, weight, and output all fit our needs very well.
The Yamaha stuff doesn't get as much press as the more common names, but they can easily keep up with, and even outperform, the more common offerings that are widely used nowadays.