AM2 portals work if you replace the keystone every time your base moves. You can automate this, but I don't like it. You can try Mekanism teleporters as well. Enhanced Portals has a crippling bug that causes crashes. Dimensional Doors is probably the best option. It may take some time to set up since you need.....I don't recall the name but it's an item you can only find in Dimensional Dungeons... to make the kind of portal you need.
Also, I have another question: I've thought about building a mobile base myself but I was put off by the time it takes for the Force Manipulator to teleport any significant distance. Did you find a method to shorten that time? Unlike their name suggests, speed modules don't do anything in that regard.