I do not see why you think those beads are rated at 7 ohms. I see no such rating. I only see a reference designator called R7, a value of 0 (which is the generic ideal value for a bead), and a notation of 4 beads 1/2W. Since all the DC power is going through these beads and this power might involve up to 20 amps, it would not be wise to include a 7 ohm DC resistance, or for that matter four times 7 ohms resistance, in series with the supply since the resulting voltage drop will be extremely large and the circuit will not work. In addition, the beads will probably burn up immediately. You may have found a part that has 7 ohms of impedance at a specific high frequency, that might be a bit better, but still not what they mean. I suspect the description "1/2 watt" merely describes the size of package the part has (like a 1/2 watt resistor size).
Those beads are included for suppression of RF currents on the wire attached to E9 TP so to avoid radiating and coupling RF to other circuits and to avoid other RF currents getting into this circuit. They are not included to assist the performance of the driver amp. Its too bad they do not provide a part number, but I think that we can choose a reasonable substitute.
You can choose a bead that is rated for high current, such as a suitable tubular bead that goes around a short length of wire, or even better, you should use a common mode choke which requires that you pass both the + wire and the ground wire through it. This type of choke works well for common mode noise in circuits that take high DC currents. For example, a part like this one (digikey pn 240-2487-ND), rated at 20 A is suitable:
**broken link removed**