Our team had a similar situation, we had 2 developers that worked remotely, in different states.
For planning, we had an all day remote meeting with everyone in the team that could be together work together in the same room, then we would share desktops with the remote folks.
Our scrum wall was through Excel. We would break PBI's down together and then add them to the excel sheet. This process was pretty tedious and sometimes it would cause people to drift off. The hardest part was getting everyone's participation.
Our stand ups are getting everyone that can get together in a meeting room with a speaker phone, then sharing an excel based burn down sheet and everyone giving their update. This would also be put on a scrum wall in that meeting room for the larger group that was together. For the devs on the phone, we would place their tasks on the wall, but just have someone move them when they give updates.
There are virtual task boards that are available for purchase, so I encourage you to look at that. We had contractors from Avanade that had created one and licensed us to use it, we tried it but ultimately gave it up.
I hope this helps.