I just bought a Yamaha RX-V573 which is last years model 7.1 AV receiver. I have been pretty pleased with it overall. I like that it can be powered on/off and controlled by my iphone so I can keep it locked in a childproof closet. I like that I can bi-amp my front channels. It had enough HDMI ports for me. I find that it doesn't reliably take my sub out of standby so sometimes I have to flip the sub on, but I don't know if that's a problem with the sub or the receiver. It was relatively cheap at $400 or so. I believe the new model is a 575 and I don't think there is much difference. I would not necessarily recommend this route for audio, but as a home theater receiver it does great.
Not sure how efficient your speakers are, but you might want to go with a 7 channel receiver that allows you to double the front channels/bi-amp for 5.1 or 5.2 playback.
I'd also make sure that your macbook pro will provide audio out over the mini-display port. I believe those newer than 2010 will, but I know older ones will do video only.