Picking an amp for Energy CB-20s

I really wouldn't worry too much about the amp. Any used receiver that you could find would work just fine. Ideally I would say look for one with a subwoofer output in the event that you decide to expand your setup.

Also how much are the CB-20s going to cost you? Vanns still has some Energy RC-10 in stock, which they are currently selling for the same price as the CB-20. Energy's RC line is very popular and since they have recently been discontinued, they won't be available new for much longer. I would still get the RCs even if for a small premium as they are better built (real wood finish), have better re-sell value and will most likely sound a bit better than the CB-20s too.

Good advice on RC10 over CB. I'd pick the RC-10 any day. Those are really quite good.

But not quite great advice on the any receiver will work part. Yes any receiver will work, thats true in the fact that you will get "sound", but not all of them are built the same and the quality differs vastly. If you do have a budget of around 300$ you can do quite well with a few integrated amps.

If you are looking for new, I'd look at the Onkyo 9555 or Onkyo 5VL. Both of them are quite good, with the 9555 getting the edge IMO

Another option is the entry level offering from NAD, this is not quite as powerful as the 9555 but has a nice clean sound.

The Cambridge audio's entry level amp is good, but I'd pick the Onkyo over that, so unless you are getting a better deal, I wouldn't bother.

A sleeper hit is the HK 3390 and 3490. This is a stereo receiver but sounds quite good unlike most entry level receivers. Its easy to find on sale and quite a deal for the prices they usually go for on ebay and the likes. If you want to save some money, the 3390 would be your best bet coming in at under 200$.

Also worth looking at are some used options, check audiogon and ebay for some used amps, or even your local stores. I have found some good integrateds for very very cheap that beat modern day budget receivers quite easily. So that might be worth looking around for, but understand that you are taking a risk with these especially the older they get.

Wow, the RC-10's just dropped another 50 bucks. Its 299 now. Thats an awesome price.

The NAD is a solid entry level amp.

I said it several times here but if you can find some used e:XL-16/25/26, they offer great value over anything new. I found some XL-16's for as little as $50 shipped on eBay and they sound as good or better than the RC10 (which I own) depending on your sound preference (e:XL have a bit more treble energy). The e:XL-26 towers really sound great and can be had for $200 or so locally via Craigslist if you're patient.

Yes, I have had/have all speakers mentioned and more.

Spend your money on quality speakers, then worry about better amps. I bought a $35 used Carver integrated that sounded better than most anything you could find new under $500- to my ears.