Which Brand 5.1 Receiver & Model for under $400 & speaker suggestions?

@andreeon - Most modern HT receivers will have 7 channels of amplification. You can use them to power a 5.1 setup. You can configure them to not have the additional 2 speakers connected, or the auto-setup will determine that the additional 2 speakers are not attached and the setup routine will account for that.You may still find a small number of HT Receivers that only have 5 channels of amplification.

You might want to go to Accessories4Less and see what they have available. I gave them a quick check and found several models from Yamaha, Denon, Marantz and Onkyo/Integra, all well within your budget. Note: Many of the HT Receivers sold by Accessories4Less are factory reconditioned. 

The one thing I learned over the years is to look for value. Especially when on a budget, the last thing you can afford to do is buy anything that doesn't really get you where you want to be. Which is why I say, forget multi-channel, and especially forget receivers. These things are pure crap. Sorry. But there simply are no good receivers, period.

What you want is a good $400 integrated amp. Stereo. Forget surround. For sure forget center channel. One is frippery, the other irrelevant. Any properly set up stereo is going to have a rock solid center image anyway. Any properly set up stereo is going to throw a sound stage at least as wide as the speakers. 

You mention "love to feel our movies and games". Well you don't need no center channel, and certainly not dinky little surrounds, to feel it. For that you need bass. Which you can't afford if you spent money on dinky little surrounds and center that you don't need. So forget all that and get another couple subs. 

You mention the sub after 5 years doesn't work. Guaranteed the sub works. The plate amp that powers the sub, different story. But you don't need the plate amp. You can connect directly to the sub and use that just fine. Ideally you would use a crossover, either the one inside the sub or DIY a simple crossover. But seriously, on a budget, turn the sub to face the wall and you can run it full range just fine. Maybe throw a blanket in there to muffle the midrange if you hear it, but whatever, you will have your bass back.

Unless of course where you want to be is surrounded by lots of wires and stuff. Above advice is if you want something that actually sounds good. Otherwise, nevermind.

Yes!
That about sounds about what i need!  I feel like im been going about it wrong all this time. I knew what i wanted but went the whole wrong way about. what do you suggest for the  400 integrated amp. Stereo?  Any suggestions would be greatly appreciated.

how about the Denon AVRX-1500?

If you and your son enjoy a 5.1 setup and you already have the speakers for it (well, apart from the currently non-functioning sub), then go ahead an pick up an AV receiver - something like the AVRX-1500 would be perfect.  If you start getting more serious about listening to music (it's a slippery slope), then you could think about an integrated amp down the road.  In the meantime, maybe consider buying an AVR with pre-outs that would allow you to connect an outboard power amplifier - this would offer additional expandability/flexibility.