You are asking for a high power device and a low power device in one package. I don't think anything like that exists. If it did, I would expect it to be a nightmare to keep stable as it wouldn't be possible to physically isolate the 'in' and 'out' ends enough to prevent feedback.
You can certainly wire a dual power tube so one side emulates a triode, wire the supressor and screen grids to the cathode but the performance wouldn't be good and you would inevitably waste lots of power in the heater circuit. Also consider thermal effects, that power stage would run very hot, probably not what you want right next to an oscillator circuit.
Brian.