i have the eon518
I don't know how they sound, but if you have one already...
As far as matching up to your 152's, you'll need a minimum of 2 EON518's/side for balance, but depending on your cross-over point you could probably get by with a single pair. The built-in crossover will not be as appropriate as you should have, so the bottom line would be to get a decent cross-over and another 518, cross them over at 75 or 80hz and let the EON's just provide some extra LF support rather than function as "real" subs.
The 152's play as low as the 518's, so if I were you I'd be looking for subs which would play down to at least 35hz before rolling off, especially for DJ'ing. KW181's would be a bit better fit.