600 more than way enough, one 500 would be good two better.
if you are listening to greater than 50% music I would even venture too say 25% go with at least the 60's and if you have extra nothing wrong at all with the 80's. If you only play movies and the occasional cd as me then M22's with dual 500's are awsome. I have 80's and will not noway go less. QS8's all the way and I find nothing wrong with my VP150.
My room is 14 x 18 speakers are 18" from wall 10' apart toed in and I have excellent sound stage ,to the point if I am listening to a Eagles DVD in Stereo or a dianna Krall CD and didn't know better, I would say the centre channel is on. totally flawless sound stage.
but....ahem you need to upgrade that amp
I would no doubt M80, VP150 QS8 and two 500's or HSU vtf3 mk3's.
as for the sound proofing some sites for your reading pleasure: and don't confuse FRP with soundproofing
note: fibreglass pink is not sound proofing
http://www.ethanwiner.com/acoustics.htmlhttp://www.acousticsciences.com/http://forum.studiotips.com/viewforum.php?f=8http://www.audioholics.com/education/aco...ent-perspectivehttp://www.studiotips.com/Also check this out
http://forum.studiotips.com/viewtopic.php?t=48 
