Subwoofer for RTI A5 speakers

I am starting to build my first home theater because my old Polk Surroundbar SDA IHT does not get loud enough being run through my Samsung Aquos LC-70LE650U.

I went with the Yamaha RX-V675 which is 7.2 with 105w per channel. I am going to run a 2.1 setup for now. I bought a pair of RTI A5 speakers and want to get a recommendation for a subwoofer to complement the speakers and the room size which is 15 x 30 and one of the 15' walls opens up to the rest of the house. If it matters I have 8 ft ceilings.

Ps I looked at the PSW10 but only being 50w I would say it’s too small.

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