[Amps] 8877 - Which Bias voltage ?

[Charlie Morrison - N1RR]

I am about to activate an RFPP-1000 amp which uses
1 - 8877 @ 2750v. (exactly what '5PRO recently described.)

My last remaining conversion change is to chose the Cathode
bias voltage to use. Here's what has been published:

K8RA-8877:   10Volt/1watt zener &  2N3055
                          " for 8.2v cathode voltage ".
                         Text indicates " bias for 18ma idle current."
                         ( That can't be for the tube idle plate
current, can it ??)

W8ZR-8877:  12 volt/50watt 1N2812
                         150ma.  idle plate current

Ameritron-AL-1500:     7.5 Zener

RA's-8877 in QST:   8.2 volt 50watt Zener for SSB
                                    22  volt 50watt Zener for CW
(Ref: Radio Handbook W6SAI / 1996 ARRL Handbook.)

So my questions are:
================
-What bias voltage is needed for SSB ? for CW ?

-Advantages / Diadvanages of using a 50w Zener vs.
  a 2N3055 & a 5 or 10watt Zener ?(Other than $$$).

Charlie - N1RR