If your wood forend is compatible with the future barrel you are planning to buy, you can ship it to Steve and he will modify it for the hanger bar system. If the forarm you currently have will not work with the new barrel, then you can buy a forarm from VV for suggested retail and then they will modify it for the hanger bar system.
What will detemine whether or not your current forend will work or not will depend on what type new custom barrel you choose. If it is the same style barrel as the one you currently have, chances are you won't need to purchase a new forend. At any rate if you do need to buy a new one, Steve can use a factory forend to modify, so it should match your current buttstock.