Yes Lynn I'm in the 'get 5.1 for now & upgrade to 7.1 later' camp. And I am also of the opinion (remember opinions are like assholes, everyone has one, and most of them stink) that Axiom subs are for people without a budget. If you are trying to stick to a budget then I say go with eD or SVS or someone like that and spend the savings on better mains and surrounds.
Your room dimensions measure 2300 cubic feet, which is almost to the limit of where Axiom recommends M22's (2500 cubic feet if I'm not mistaken?). So perhaps even a set of M60's would be in the running? Not that you wouldn't enjoy the M22's, just thought I'd mention that.
But don't take my advice too seriously. After all I started out with a speaker budget of two grand and I would up spending that alone on my EP800!
