If my google search didn't lead me astray, the 7100 would be plenty to handle the Polk 7200s. There are a number of Axiom users in this forum, using both 7100 and 755/770 amps - some of them may be able to shed some light on how Axioms fare with both amps. Before you commit, you might want to decide if you'll be moving from your current 5.1 system to a 7.1 setup - if you think you might, but still want the 200W per channel, you could either consider the 770 or possibly add a pair of M200 monoblock amps at a later date.

Assuming you are using a powered sub, you connect it directly from the 950's subwoofer output to the sub's amp - this is not only a conveniently simple arrangement, but also allows you to make full use of the 950's bass management features. The cables from the 950 to the amp are simple analog audio cables - the same type used to connect the left and right analog audio from a source (VCR, etc.) to a receiver. They are available from many sources, including Outlaw (their PCA is a very well made analog audio cable).

------------------
gonk -- 950 Review | LFM-1 Review | Pre/Pro Comparison Chart | Saloon Links