Some more details on your usage i.e. Movies % & Music % & even the dimensions of the Living room will help FM to suggest.
In my opinion for a 320sqft room, i think you should be looking at 700... these Soundbar certainly comes at premium price & if you need to add bass module + surround speakers that will set you back by another 92k which IMO is overkill. It sounds good, does the price justify the specs & features? again its personal choice
I would suggest take a look at New JBL Bar 9.1, its future loaded & complete VFM.