Originally Posted by SalsaShark

Most cost effective way to make this work would be to go with a barend shifter and pair of Tektro brake levers. These brake levers are available for short or long pull, so be sure to get long pull designed for linear pull brakes or Mtb disc calipers You can pick up an 8-speed indexed barend shifter set, which will shift your FD with a friction barend, and your RD with either index or friction. With this, you could keep your current derailleur setup. You should be able to setup everything including cables for under $100.