Ok. I've gone and purchased an Avant 55.
I have also purchased the new clamper system from STB Brackets, so hopefully that will arrive before the TV.
I'm using the Avant as a 3.1 with my BL3s as rears.
I was considering using the BL18s as rears, but I am more than happy with the BL3s and considering that I have not been using them... it sort of makes sense.
I will be using the Installation company to hook up my Foxtel, PS4 as my Blu Ray player and an Apple TV which I will have on the clamper system instead of inside the TV - in case something goes wrong with it, i think it will be easier than dismantling the TV if it's in the hidey hole.
This will be my first BV. BV's haven't made sense to me in the past, but this Avant does.
I'm having a glass of Sparkling in celebration.
PS. My back room where the Avant is going is too small for a BL19 or additional front speakers.