Yeah Bro, we're using a Yamaha RX-V3800.
I have not auditioned the LSiM extensively but I did have a chance to compare bookshelf models of the three lines: LSiM, LSi and RTi. RTi still the best based on performance/price, and I still like the LSi over the LSiM.
Kung A5 over the A3, if you've a tight budget, you might consider putting the additional mulah into a second or higher model sub, or maybe something else. The A5 only adds a second driver for the midrange and bass. I think you'd get better results having your AVR relieve your front of delivering the lows thus being able to do the midrange better, and having your sub(s) do the bass.