What size space, main music system?
I would use those speakers in a second system, and get new larger speakers if the space allows. Or, no 2nd use, sell them to help pay for the speakers you move up to.
I use and very much like my Wharfedale Diamond 225, similar driver sizes and efficiency, in my office (with a single sub adding just enough that they don’t sound small).
your interesting amp does not appear to have pre-out/main-in so not ideal if you want to try a stereo pair of self-powered subs.