Debian on MacBook Pro 11,4 (15" Retina) - TouchPad and WiFi

Thanks for reading this. I have a mid 2015 MacBook Pro, 15" Retina, the 11,4 model. I installed Debian Jessie, running kernel 3.16, on an external hard-drive and can boot into it. I only have two problems: I can use the mouse fine to point and click but I can't do anything that requires multitouch. For example, I can't scroll or right-click using the force touch trackpad. The Debian website says all the new trackpads should be supported so I am lost as to what to do. The system settings pane has only two options under Mouse/Trackpad which are not helpful. My other problem is that I cannot get the internal WiFi thing to work. I got the proper driver and installed it (brcmfmac) but it says I need kernel 3.17 for it to work; when I check the available upgrades using apt-get cache search linux-image they are all 3.16. I am new to Linux so I don't know how to proceed. Any help would be appreciated.