By chance I have very similar parameters as yours: same amp, almost identical room dimensions, and I never listen beyond mid-volume levels. For speakers I have PMC FB1+ and I'm very happy with the match between them. They retail for $3.3K but can be had for less via demos, sales and used models. Right now I think they have some at Acoustic Sounds.com.
Although the 2BSST is "only" rated for 100 watts at 8 ohms, I've never needed more than that. It's just a smart, clean amp that can power plenty of "regular" speakers that don't need 500 watts etc. , listeners that go for mid to mid-high volume, or in moderate sized listening rooms. With that in mind I'm guessing you'll have plenty of speakers to choose from.