I may not be understanding you correctly, but your O2 concentrator is attached to the torch on a hose separate from the propane hose. Propane is not routed through the concentrator. In a typical hose setup from a welding store you get a red hose and green hose attached to one another. They can be carefully cut apart. The red is for propane and the green for the oxygen. As Dale mentioned, 12 feet away from the torch will work for both the gas regulator and the oxygen concentrator although there is nothing wrong with either the tank of propane or the concentrator being closer to the torch than that. Three or four feet away may be OK as hot glass probably won't spit any farther.
For the propane, you want the pipes and hoses to be higher than the top of the tank. Don't let the hose dip down below the top of the tank - this keeps impurities from collecting there.