Hi Fred. Welcome.
I think we need more information.
How much, exactly, do you want to spend and when?
What kind of amplifier / processor are we talking about? Is that part of this acquisition cycle or not?
What about source components? Are you listening to CD's, Vinyl, MP3's, etc? Is gaming part of this equation?
Do you have preferences or restrictions regarding the size of the speakers or the form factor?
A few thoughts:
I totally agree you should get the best main speakers you can afford, and that if you get floorstanders, you could go without a sub for a while. If you get bookshelves (M22's or M3's), you're probably going to want a sub right away.
Since you'll be substantially upgrading your TV in the near future, you're going to spend quite a bit of time in Home Theatre mode. Maybe more than you think. The surround speakers are going to make a big difference.
The Axiom subs are tremendous. However, depending upon your location (are you in Canada or US or elsewhere?), they might not present the best value proposition if you are on an extremely limited budget.
Everybody who is a regular here REALLY digs Axiom speakers; otherwise, we wouldn't hang around. There are lots of options and many paths, but you have to be realistic about how much you can/should spend and when you can spend it.
Personally, given what I know now, here's the progression I'd go through:
1. Get a pair of M60's and run 2.0. Unless you ULTIMATELY WANT bookshelves. If so, get M3's or M22's. If you have the money, by all means get M80's.
2. Get a pair of QS8's and run 4.0. QS4's don't save THAT much money. If you REALLY need to save money on the surrounds, get M2's instead.
3. Get a decent sub within your budget and run 4.1.
4. Get as much center channel as you can afford (even a single M2 is awesome) to go to 5.1.
There are lots of people that will say how important the center channel is for HT. It really depends upon not only your budget and your room, but also your listening habits. It's more important sooner if you regularly share your viewing with several other people. If it's just you, or you and your SO sitting close together, a phantom center channel will be pretty satisfying.
Have fun with the journey.
