With your current equipment, the only thing lacking is Receiver volume/input controls from the patio. IR components would solve that issue.The laptop would be controlled by an app on the tablet or netbook pc.
Upgrading to Yamaha's Aventage line would eliminate the need for IR equipment since all of the current models have the web control feature available for multi-zone use. However, then you'll need a network connection from Receiver to router (ethernet or wireless dongle). The Aventage RX-A720 would probably be comparable to your current Receiver and has the airplay feature, but airplay certainly isn't necessary. You could save a couple of hundred bucks and get the A710 instead.
I prefer using a netbook pc over tablet for my outdoor zone because I find it easier to handle, but either would work fine.
With outdoor speakers, there are a myriad of options. Most are very well built to withstand the elements. I bought pairs from Amazon and Crutchfield. Polk Audio Atriums, PSB CS1001, and the Axiom Algonquins. I don't recommend the Axiom product, but quite sure Polk's Atriums have something to suit your needs. They have a larger selection than any of the competition from what I've seen.