I used to like Boston Acoustics in the 90's, but haven't heard them since.
You can get that AVR on accessories4less for $450 right now.
You should plan on $350- $550 on a sub.
That leaves you $1000 -> $1200 on a 5.0 or 7.0 speaker setup.
Ascend's aren't totally out of range, if you want to go there - you could make it work.
This Ascend 7.0 package is just a bit more than that...but not much:
CMT-340 SE front pr + CMT-340 SE center + CBM-170 SE rear pr + CBM-170 SE rear pr
+ $130.00 shipping
+ XXX accessories and mounting
Cut that down to 5.0 and get your final two CBM-170's later and you'll be in the green.
Toy with their package calculator to see if you find something that works.
Start with 3.1 and slowly move to 7.2 if you want.
Heck, I was so happy with my Wharfedale Diamond 10.2's that I'm still using them in a 2.1 setup for TV, Movies and Music! Every time I think about getting the matching, $300, center channel, I find something else to buy instead. Recently a new turntable trumped the center speaker. Previous to that it was my garage-sale hunting for a basement system.
Eventually I'll get the Diamond surround package together as I originally planned, but I'm really finding that 2.1 sound can be pretty good (especially if you are only used to HTIB's or the built-in TV speakers). I tend to listen to music-mostly, so I even find myself listing to 2.0 sound in "Direct Mode" quite a bit.
One thing I like about starting small and then adding, is that you do get to see how each addition changes the sound/experience. When I get my center channel and upgrade to 3.1, I know I'll enjoy the added bonus. If I don't, I'll send it back!
But by the time I'm surrounded with the 5.1 system, my ears will be well trained and I'll know exactly why I have each piece - and what it does for me.