How do I make a 3D shop?

I have the shop Gui's made, but when I try to make the part offset from the middle, when you move around the camera the part does not stay in place.

local ang=0
while wait() do
    if game.Workspace.CurrentCamera:FindFirstChild("Part")then
        ang=ang+1 --This just makes the part rotate
        game.Workspace.CurrentCamera.Part.CFrame=CFrame.new(game.Workspace.CurrentCamera.CoordinateFrame.lookVector*3+game.Workspace.CurrentCamera.CoordinateFrame.p+Vector3.new(6,0,0))*CFrame.Angles(math.rad(ang),math.rad(ang),math.rad(ang)) --This is the formula to put the part in the middle of the screen then offset it by 6 on the x axis.
    end
end

Help?