well congratulations on getting a mac they are far better
ICE3 is the primary front end in crrent development. NASAIR is being updated on occassion as well.
yes you will be able to sync your phone and use it to tehter easily enough if you jailbreak your phone. There are severl VNC programs on the App Store or Cydia to control parts of the PC
There is no GPS software for the mac that is reliable enough to use like roadrunner
If you need it to work like road runner you might want to stick with Road Runner because there is nothing even consierably close to it for OSX.
I would recomend the mac mini, I had one in my car and the all inclusive and small foot print is great. The new one has enough on board USB ports to power almost everything with no hubs. The laptop that you have should work fine, I think that ICE3 is able to run on non intel machines.