NHT SuperZero might be a good option.
Only problem with that option is that the OP mentioned using a 80Hz crossover setting...
The SuperZero does not play down to 80Hz... it starts rolling off up around 150Hz.
http://www.hometheater.com/content/nht-superzero-20-speaker-system-ht-labs-measures
Wall mounting will give a little low end help, but even then I'd think 100Hz is the absolute minimum xover one should use... and if pushing the volume knob up high, 120Hz or even 150Hz would be more appropriate.
This isn't necessarily a bad thing, provided the sub can be placed near the mains, ideally between them somewhere, to avoid localization of using a higher 120Hz xover setting.
