Saradomin's light is completely useless. Zamorak is currently about the same gp/hr as bandos but slightly better, it's not crowded at all though. Zamorak spear's drop rate is 1/128 at a ge price of 8.5m, staff of the dead is 1/512 at a ge price of 15.5m and hilt is 1/512 at a ge price of 1m.
If you do the maths that's an average of 100k per boss kill from the big drops only and if soloing you might get about 10 kills per hour if you are maxed melee and banking fast, but trio should be best since you can average 30 kills per hour and can last for 100+ kills per trip.
With all drops considered I think you should average about 1.5m/hr at zamorak.
P.S. Get kc on imps, there are 4 imp spawns in the stronghold.